It is though. Imagine if every online forum was forced to promote government propaganda. That's not free speech. So to some degree, forum discretion is speech.
Just imagine if every telephone companies was prevented from discriminating on the basis of the speech....
Oh wait, that is literally how common carrier laws work. They are basically, forced to sell to everyone, and have to allow anyone to make speech over their network.
Instead, I am pointing out the ridiculousness of saying that every single instance of the governement "enforcing" speech, in the context of powerful platforms, is somehow some huge infringement on free speech.
Because clearly, we are OK with the government requiring phone companies, which are platforms, into allow most people to make phone calls.
Therefore, you cannot come out, swinging very hard, with this free speech stuff, when, if I were to guess, you are totally OK with phone companies being covered under common carrier laws.
So you need to either chill with this whole "free speech" argument, or you need to instead come out and say that common carriers are some horrible, really evil thing. Pick one.
Oh wait, that is literally how common carrier laws work. They are basically, forced to sell to everyone, and have to allow anyone to make speech over their network.