You can’t moderate a free speech platform, that’s the thing. So I can realistically harass someone online and be well within my bounds of “free speech”. I can say the most vile things ever and be well within my bounds of free speech
To me it seems a theoretical discussion about the definition of free speech that is mixed up with a business discussion which makes no sense.
There are tens and possibly hundreds of exceptions to free speech as demanded by US law, and they are free speech purists.