I don't think this was the case as I wasn't a Buzz user. And yes, it wasn't _really_ a social platform, but you could share items from your own feed to other mutuals and converse under the thread that you (or they) shared. A couple other readers like Inoreader and TheOldReader later implemented stuff like this, but without the large user base that Gmail had it was pointless.

Its limitations were part of what made it thrive.