With constitutionality free speech the government shouldn't be allowed to force a private entity to amplify or censor speech. And don't get me wrong. I was happy about the ban in this moment.
On the other hand I wouldn't like to give all moderation power to private entities alone. If not opportune with current business model, company ethics are quickly changed (e.g. don't be evil). As long as you have small decentralized shops and platforms that's ok. With concentration of power a private company nearly acts like a utility. Maybe some kind of neutral and elected ethics committee could help large private platforms to maintain transparent and democratic standards. Would they have blocked him even earlier?