My bot/overlay setup catches host and auto-host notifications in chat, via a separate connection logged in as me (would be better if the bot could see them itself as a channel editor, but that’s a separate issue), and uses those events for a “thanks” in the overlay as well as an automatic shoutout in chat for those I’ve whitelisted.
That has been happening reliably until April 24th. After that evening, I only seem to get auto-host notifications if “for up to N viewers” is part of the message, and I’m not even certain that I’m getting all of those. For other auto-hosts, which I only notice if I pull up my Twitch dashboard immediately after I stop streaming, I see nothing. Manual channel host notifications still happen normally, whether there is a viewer count or not.