I personally do not have a use case. I’m helping with a library that consumes the TMI and I was asking to make sure I (we) are doing things properly. I’m not focused on ‘turbo’ in particular but the general depreciation of those tags.
So the badges tag is for display purposes in chat. Makes sense. That’s it’s purpose as a tag.
I guess since you can hide them that Twitch wants to remove the flag for it.