Adding @Medhabansal. :)

We just need an enwiki sysop to mark the tag as inactive.

@MusikAnimal may help.

I don't see a "delete" or "deactivate" link under Actions, like I do for some other tags. How do I mark it as inactive?

I did blank the description, so it at least doesn't stand out as badly in the tags list.

In T187915#4028335, @Catrope wrote:

We just need an enwiki sysop to mark the tag as inactive.

How can we find one of those sysop?

By looking through https://en.wikipedia.org/wiki/Special:ListUsers/sysop or by typing @Ragesoss into any Phab task involving the Wiki Edu Dashboard. ;-)

As an enwiki sysop I confirm there's nothing I can do here. The tag management interface doesn't seem to let us locally manage OAuth tags, which is probably correct, except for the fact that OAuth doesn't provide any way of managing them I can see.

Tagging MediaWiki-extensions-OAuth for awareness.

Tag names are localizable the same way other i18n messages are. There are edit links to the relevant messages on Special:Tags.

We can disable the OAuth app, in which case the change tag will be removed from ChangeTagsListActive but not from ListDefinedTags. I am not sure of the exact UI implications, but it will at least disappear from the RecentChanges UI.

Maybe if the OAuth app is oversighted, the change tag should be disowned by the extension entirely (at which point admins can delete it).

There is no way to change the name or description of an existing OAuth app (those are the default values for the tag name and description). It's a somewhat tricky problem due to the security implications.

See also T60937: Add "under development" stage before "proposed" stage for OAuth consumers which would provide the foundation for not tagging edits made by test apps.