I checked the pull request linked in T362854 (https://github.com/wbstack/queryservice/pull/113) to find the updated URL.

The only difference from the entry for this service in our current wikidata allowlist is the use of https:// instead of http://
https://github.com/wikimedia/operations-puppet/blob/production/modules/query_service/templates/allowlist.txt.epp#L22

I can see that the http based query is working at the moment.
https://w.wiki/BBJQ

So I can make a patch that updates the allowlist to use HTTPS instead, but maybe this would catch some people unawares.

Do you think we should add both schemes and allow users to update any saved queries before removing the HTTP support, or will it be sufficient to swap the URL?

Change #1072734 had a related patch set uploaded (by Btullis; author: Btullis):

[operations/puppet@production] Update the URL of the WikiPathways SPARQL endpoint to use HTTPS

https://gerrit.wikimedia.org/r/1072734

In T364448#10143829, @BTullis wrote:

but maybe this would catch some people unawares.

The federated querying with the http URL has not been working, so I do not expect that people will be surprised.

Do you think we should add both schemes and allow users to update any saved queries before removing the
HTTP support, or will it be sufficient to swap the URL?

Swap should be enough. The http version does not work (practically; theoretically it should, of course).

In T364448#10143874, @EgonWillighagen wrote:

Swap should be enough.

Great! Thanks for the guidance.

The http version does not work (practically; theoretically it should, of course).

OK, got it. Is this query not working, then? Have I misunderstood something?
https://w.wiki/BBJQ

Oh, apologies. That indeed used to not work. But it is now. It is likely still fine to only list the https one, as the industry standard.

Change #1072734 merged by Btullis:

[operations/puppet@production] Update the URL of the WikiPathways SPARQL endpoint to use HTTPS

https://gerrit.wikimedia.org/r/1072734