This was removed, which is why you can’t find this on the third party developers site: Twitch Developer Documentation | Twitch Developers
This is (generally) due to how EventSub does “cost” was altered (since that previous post was made) and generally speaking applications don’t need a limit increase.
If you have done an oAuth loop for a streamer, then topics for that streamer are cost 0.
So if you are listening for stream.online from lirik they are cost 1
If lirik then authenticates your application/ClientID, then stream.online becomes cost 0
Which lets you fit within the limit as authorized streamer topics are 0. So in theory you can have infinite subscriptions, as long as the entity involved has authenticate your app.