Thanks, but although it's a third-party platform, I think that Adobe decides which login to use. I mean, I have to login via my Adobe ID, that should be proof enough. There is no global login for uservoice.com, there is also no forum at UserVoice.
Of course I could contact Adobe directly, but I thought maybe some other users also wondered and already found out what happened to their old accounts.
Btw: I did not post in this sub-forum here, I created my thread in a more suitable forum (because it's not the Adobe account itself). Someone moved the thread.