Protect nicknames for usergroups members

[minusQuantumNeko]

Afaik, at the moment if GMT/Alumni/etc. group member changes their nickname, their past ones can be taken by anyone else. But I believe this shouldn't be the case, as their nicknames are as important as let's say ranked mapset host's.

[peppy]

historically team name change weren't allowed. and i'd prefer that's still the case..

[minusQuantumNeko]

historically team name change weren't allowed. and i'd prefer that's still the case..

Well, there are a few issues with that.

1. There is no warning about it when joining teams, at least not for Project Loved.
2. What if a user changed their username recently, but many still use their old one to refer to that user?
3. What if an Alumni member decides to leave osu! for years? Someone could very well take their username.

[peppy]

project loved would not be protected anyway.