The username change sucks for sure, and I was so confused while reading the pretext for it, it really sounds like bullshit.
However I still think it's a great platform for its use cases and I wouldn't stop using it just because of the username change and the Nitro stuff.
If an open source alternative looks promising and gathers a good user base, I'll consider switching as long as my friends are into it, but it was hard enough to convince them to use Signal instead of Messenger lol