Saying something like “Refresh the tree of liberty” or “hang the traitors” etc. still doesn’t rise to the level of illegal speech or an imminent call to violence which is the standard under the law. In fact, if you were to claim language like that crosses the line we would have to pull books off library shelves because the same language has been used repeatedly by politicians in American History. I’ve also seen similar language used in reference to Trunp like “He will get what’s coming to him if he comes to our city” etc.
It’s distasteful but it’s legal and part of our political culture.
Distasteful speech is legal and so is kicking distasteful speech off your private platform. The primary limitation on what businesses can and can't do with who uses their platforms are that they need to avoid affecting protected classes.
If you think we need to protect MAGA supporters as a class, I just flat out disagree that there's any cause for it. That group of folks are largely already brimming with privilege that protects them (see walking away from storming the Capitol after killing multiple people).
If you think that the government should force private entities to not enforce consequences to speech they disagree with, I believe the government would struggle to prove that that doesn't itself impact the free speech rights of the private entities and it face immediate law suits to overturn such a law. The 1st amendment protects us from the government, not us from each other.
In the context of discrimination law, there is a commonly-held misunderstanding that "protected class" refers to a group of people, but actually, it refers to a classification.
A particular race is not a protected class. Race is a protected class.
It’s distasteful but it’s legal and part of our political culture.