By the way, you might know that in California, shopping centers may have to allow people to engage in some expressive activity on their private property, even when they don't endorse the speakers' message:
Thanks! That’s what I was trying to refer to. But that seems different in a few ways. First, there’s actually physical open spaces in malls where the public is invited—you don’t have to shop. Second, the protest in a mall is ephemeral. Youtube is like a store in the mall, not the open forum (I don’t think Macy’s would be required to have a protest in its store); the internet is like that open space. Second, extending this to YouTube would require YouTube to proactively host a video on its servers, pay for costs to play it, and host it forever (until the protestor takes it down).
https://en.wikipedia.org/wiki/Pruneyard_Shopping_Center_v._R...
(I don't mean to suggest that this provides some kind of obvious solution to Internet content moderation disputes.)