The Spanish Wikivoyage is all but done removing their links themselves, they're fine with the extension removal.

The Dutch are looking into it, making sure that the Wikidata links have 1:1 correspondence to RelatedSites.

No word on Greek or Polish yet.

I've found a Portuguese translator that I'm reaching out to personally.

Great, thanks for the update @Keegan!

CC @Jrbranaa This is the ticket to deprecate RelatedSites on the top 5 wikis as I mentioned in my last update.

RelatedSites is used at the German Wikivoyage because the user namespace is not supported by Wikidata. We need a set of interwiki-links like [[commons:...]] for sister projects similar to interlanguage links [[en:...]]

In T199367#4437714, @RolandUnger wrote:

RelatedSites is used at the German Wikivoyage because the user namespace is not supported by Wikidata. We need a set of interwiki-links like [[commons:...]] for sister projects similar to interlanguage links [[en:...]]

The extension was not meant for linking to user pages. The better way to handle user namespace links is by having Userboxes or by adding the links on the User page instead of the sidebar.

Portuguese
Pre-Wikimania translation request didn't come through, so I found a new person today to ask:
https://www.mediawiki.org/wiki/User_talk:Hamilton_Abreu#Translation_request

Spanish
I think that they are ready for removal, having cleaned up the pages themselves. I suggest you post there for affirmation as the person responsible for the change when it goes live, you can post in English (my first post is already archived): https://es.wikivoyage.org/wiki/Wikiviajes:La_posada

Dutch
The Dutch seem confused about if all the links are 1:1 or not, but overall I don't think they care. I suggest you followup with them, English is fine: https://nl.wikivoyage.org/wiki/Wikivoyage:Reizigerscaf%C3%A9#RelatedSites

Polish
Doesn't seem to be a cohesive community to ask, but one person volunteered to help remove links by script. You can contact them in English on their Polish Wikipedia talk page: https://pl.wikipedia.org/wiki/Dyskusja_wikipedysty:Katafrakt

Greek:
No response, doesn't seem to have a community. I suggest just doing it ourselves.

Portuguese posted:

https://pt.wikivoyage.org/wiki/Wikivoyage:Bar_dos_viajantes#RelatedSites

Spanish follow-up posted: https://es.wikivoyage.org/wiki/Wikiviajes:La_posada#RelatedSites_removal

The Dutch seem to have cleared the links and are okay with un-deploying the extension: https://nl.wikivoyage.org/wiki/Wikivoyage:Reizigerscafé#RelatedSites

For Polish, since we are writing a script to remove the links in T201215: Write a script to remove RelatedSites links from pages on a given wiki, we could just use that.

@Keegan - When we remove the links from the pages, do you think we should let them be on the user pages or should we clean those up too? Technically speaking, it's no extra work though I'm wondering if people would be averse to a bot touching their user pages, even if it's to remove dead links.

In T199367#4488975, @Niharika wrote:

Spanish follow-up posted: https://es.wikivoyage.org/wiki/Wikiviajes:La_posada#RelatedSites_removal

The Dutch seem to have cleared the links and are okay with un-deploying the extension: https://nl.wikivoyage.org/wiki/Wikivoyage:Reizigerscafé#RelatedSites

For Polish, since we are writing a script to remove the links in T201215: Write a script to remove RelatedSites links from pages on a given wiki, we could just use that.

@Keegan - When we remove the links from the pages, do you think we should let them be on the user pages or should we clean those up too? Technically speaking, it's no extra work though I'm wondering if people would be averse to a bot touching their user pages, even if it's to remove dead links.

Bots editing userpages to remove dead links should be fine. I think if we're moving the links, we should do so 100%.

In T199367#4489005, @Keegan wrote:

In T199367#4488975, @Niharika wrote:

Spanish follow-up posted: https://es.wikivoyage.org/wiki/Wikiviajes:La_posada#RelatedSites_removal

The Dutch seem to have cleared the links and are okay with un-deploying the extension: https://nl.wikivoyage.org/wiki/Wikivoyage:Reizigerscafé#RelatedSites

For Polish, since we are writing a script to remove the links in T201215: Write a script to remove RelatedSites links from pages on a given wiki, we could just use that.

@Keegan - When we remove the links from the pages, do you think we should let them be on the user pages or should we clean those up too? Technically speaking, it's no extra work though I'm wondering if people would be averse to a bot touching their user pages, even if it's to remove dead links.

Bots editing userpages to remove dead links should be fine. I think if we're moving the links, we should do so 100%.

Gotcha. Thanks.

In T199367#4439235, @Niharika wrote:

In T199367#4437714, @RolandUnger wrote:

RelatedSites is used at the German Wikivoyage because the user namespace is not supported by Wikidata. We need a set of interwiki-links like [[commons:...]] for sister projects similar to interlanguage links [[en:...]]

The extension was not meant for linking to user pages. The better way to handle user namespace links is by having Userboxes or by adding the links on the User page instead of the sidebar.

When I personally wrote the extension in 2007, and it was of course intended to link the user pages. If we remove RelatedSites then we have no substitute. If it would be allowed to add user pages to Wikidata we would not have any problems. But as I already told the interwiki sidebar links are missing which could be a substitute. At the German Wikivoyage we do not use userboxes in that extend as it was used in Wikipedias, and we do not use it for interwiki links -- it is unnecessary work for admins. And why we should use userboxes if we have "in other projects" on the sidebar?

We should add interwiki support to Wikidata's "other projects" first.

By the way we lost a lot of authors because the foundation didn't keep all promises done before the start of Wikivoyage. And the foundation accepted that RelatedSites is an important extension to keep.

In T199367#4490660, @RolandUnger wrote:

In T199367#4439235, @Niharika wrote:

In T199367#4437714, @RolandUnger wrote:

RelatedSites is used at the German Wikivoyage because the user namespace is not supported by Wikidata. We need a set of interwiki-links like [[commons:...]] for sister projects similar to interlanguage links [[en:...]]

The extension was not meant for linking to user pages. The better way to handle user namespace links is by having Userboxes or by adding the links on the User page instead of the sidebar.

When I personally wrote the extension in 2007, and it was of course intended to link the user pages. If we remove RelatedSites then we have no substitute. If it would be allowed to add user pages to Wikidata we would not have any problems. But as I already told the interwiki sidebar links are missing which could be a substitute. At the German Wikivoyage we do not use userboxes in that extend as it was used in Wikipedias, and we do not use it for interwiki links -- it is unnecessary work for admins. And why we should use userboxes if we have "in other projects" on the sidebar?

We should add interwiki support to Wikidata's "other projects" first.

By the way we lost a lot of authors because the foundation didn't keep all promises done before the start of Wikivoyage. And the foundation accepted that RelatedSites is an important extension to keep.

Firstly, my apologies @RolandUnger. I did not know that you were an author of the extension.
The decision to remove RelatedSites was made in T185206: RelatedSites: Code stewardship review which is a better venue to discuss this. Let's take this question there and see if others have opinions on how this could be resolved.

Over two weeks, no reply for Portuguese Wikivoyage. It's a project we'd have to do ourselves. Closing out this task.