The platforms write their own terms of service. I'm sure they're pretty broad to give them license to do basically whatever they want. Are there many examples of platform moderation decisions that are unequivocally out of touch from their terms of service?
Facebook could say "you can't post harmful content" and then it's up to Facebook (moderators) to define what "harmful content" is.
The YCombinator/Hacker News Terms of Use https://www.ycombinator.com/legal/#tou https://news.ycombinator.com/newsguidelines.html is quite broad and gives them license to remove basically whatever they want (as it should - it's their website, they should be able to run it as they see fit)
Eschew flamebait. Avoid generic tangents. Omit internet tropes.
Please don't use Hacker News for political or ideological battle. That tramples curiosity.