I am surprised that the API (Assuming it’s the API) makes public streamers bans.
Shouldn’t this be private? It’s weird to see Twitter accounts announcing banned streamers before they even get a mail with the reason.
Wouldn’t it be better to remove this information from the API.
Not even Twitch shows the users what happened with a streamer, it only says
Sorry. Unless you’ve got a time machine, that content is unavailable.
Which not always means a ban if I’m correct.
Helix/Kraken reports a “banned user” as 404 not found, so you can’t tell the difference between (when looking up by name or ID) a ban, a delete, or a rename (when looking up by name).
TMI/chat will returned a suspended message on join attempt but that in itself doesn’t mean anything on it’s own (msg_channel_suspended NOTICE Message IDs | Twitch Developers)
The Twitter account you refer to I don’t know how it does it.
So to my knowledge they are either poking something they shouldn’t or assuming that a Suspend TMI message means they are banned.