Yep; different circumstances though.

Beeper Mini was shut down by Apple, which allegedly identified the requests from Beeper Mini and terminated access to its servers.

Nothing Chat/Sunbird, on the other hand, was shut down from themselves, because they were caught mishandling user information. The method itself was not shut down, rather they discontinued their own implementation. (Fwiw, Beeper has a similar implementation on another product of theirs, which remains functional as far as I know. )