I'ce seen examples, which I've personally confirmed and seen, of twitter blocking any mentioned of mastodon... that alone is pretty extreme censorship, way more so than most things
In this case its worse because its the whole of the fediverse, meaning it isnt even politically motivated, its just used to silence another entity out of existance (or at least trying to)
Yikes… that reminds me of how #Facebook blocks links to #rebased instances (or at least #Gleasonator)