I like to think I'm responsible for at least a few of these blocked instances.
https://fba.ryona.agency/?domain=merovingian.club
Check out all of the butthurt reasons listed, it's hilarious.
Interesting. Easily bypassed however by using a messenger that is actually private.
Many open source candidates out there but a great one is SimpleX-Chat. If you don't have FDroid installed (open source appstore) then do that first and then install: https://f-droid.org/en/packages/chat.simplex.app/