Someone either forgot to remove it or it was readded when some documentation was updated.
A common mistake with the Twitch Docs.
Err I can’t find it in the docs, Reference | Twitch Developers
Other than a “typo” on Reference | Twitch Developers
Multiple user IDs can be provided, e.g. /moderation/banned/events?broadcaster_id=1&user_id=2&user_id=3
under
URL
GET https://api.twitch.tv/helix/moderation/banned
thats a copy/paste typo and not documentation for the endpoint.
Cites the removal of the documetnation for the endpoint on March 18th.
What you are looking at in the docs is a typo in the “Get banend Users” docs