Everything about this seems incredibly suspect. Reddit wouldn't ever ban anyone for suggesting an alternative (there's a whole subreddit dedicated to that). This just seems to be a shill capitalizing on the news, plain and simple.
They absolutely do. Try linking to rdrama.net, you'll get shadowbanned.
On whole plebbit or just some subs?
Which one?
It comes complete with a wiki page that lists many of them: https://www.reddit.com/r/RedditAlternatives/comments/yttdlc/...
(edit) The original post by TFA ( https://lemmy.ml/post/1152281 ) with the link text of "Asking multiple third-party app devs consider Lemmy" is to https://www.reddit.com/r/RedditAlternatives/comments/13ylrt6...
But there's a difference between posting that once, or twice... or even thrice vs cross posting it a score or more ( https://i.imgur.com/scny5VP.png ) where it becomes problematic.