People do go to Facebook for their news. Whether you like it or not, or think those people are fools, it's true. What Facebook decides is deserving of censorship matters because we have to live with those fools.
If you believe that Facebook is something more than a toy, then it seems reasonable that they'd have freedom of expression, press, speech, so on. As such, if people choose to get their news from Facebook, it's no different than them getting their news from Reuters, FOX, the New York Times, or Bloomberg. Surely you wouldn't imply any of them wouldn't have editorial control.
Comment sections on news outlets can remove whatever they want, I don't see why it'd be any different for Facebook, if you genuinely consider them a news outlet.
Legally im sure they can do almost whatever they want in terms of filtering/censoring/etc, so I don't think talking about their legal obligations or rights is very interesting.
They have behaved a certain way for their 15-20ish year history, and I'd argue that it was mostly as a neutral platform for communication, not really anything resembling a publisher, and they've gained an enormous userbase under this model. I think this is the correct way for a platform like facebook to operate, and that's in part why I use their platform.
I don't welcome them deciding to fundamentally change how they operate and begin filtering more content, especially due to what I view as partisan political reasons.
Comment sections on news outlets can remove whatever they want, I don't see why it'd be any different for Facebook, if you genuinely consider them a news outlet.