Proof is sort of important though wouldn't you agree? If we could just accuse people or businesses of being guilty and that made them guilty we wouldn't really have any freedom at all as you'd be subject to the fanciful whim of anyone who wanted to accuse you of anything at all.they most likely had a part in it .. finding the proof is the issue ..
Edit: by the way if there is concrete proof that the US government made Twitter ban Trump, then by all means I'll take a different position on this, but until then it's just a private business making business decisions.