OP's point is that creating a favored restricted platform natrually allows for restricting of free speech because of a private "compnay policy". ("allows for" is doing heavy lifting here btw)

Should a government choose to communicate essential facts only through a restricted medium it is obviously no longer serving the larger public interest and thus no longer a government of "a people for a people".

Musk and fellow techoligarchs can have their private platforms.

Free peoples' governments and responsible social organizations must treat them as 'for profit entertainment channels' and not give them any legitimacy in the political space.