AWS gave Parler until Monday to either remove everything that supported violence and hate speech, or find another host. 

[my thoughts on part of what happened...from an Admin's point of view and not a political one]
Every platform where Trump had a social networking/media account has either muted, blocked or completely deleted his accounts.  I just had a thought on that...that it wasn't necessarily blocking him (although I'm sure that was a big part of it on some accounts), it was taking care of the resulting comments before they even got started.