I feel like you missed the core issue here. Parler wasn't kicked off because bad actors were planning terrorism. They were kicked off because they refused to moderate the content from those bad actors.
You just picked out two companies who spend billions on content moderation. Also planning a protest and planning intentional violence against Congress in the United States Capitol are completely different things.
Your whataboutism was not only a thinly veiled attempt to avoid the subject at hand- it was also completely irrelevant and demonstrated a deep lack of understanding of the situation.