A nuance: AWS de-platformed Parler for its insufficient moderation on violence-inciting discussion, not for existence of such discussion. Not that I agree with or disagree with AWS decision, but it's worth having a nuanced discussion. A larger problem I see in the US is that many, if not all, nuanced discussions are considered evil by the left or by the right.

Have you seen Parlor? It actually hosted and glorified violent videos. In comments, people were celebrating beating of cops.

As for BLM, I don't know if they have any central location where they plan any violence and then share videos of that.

citation needed

I think you're setting an egregiously false equivalence here. BLM didn't openly plan to kill 80 people on Facebook. And if the right-wingers had merely planned to have protests and some crimes happened to be committed at those protests, Parler wouldn't be shut down now.