Some of the opinions that differ are really bad ones.
It made me wonder how unlikely or impossible an event has to be before it would no longer be considered a real threat by whoever or whatever flags posts like that. Firing billionaires into the Sun? Hmm, probably too close to home. Sending them light years away to fire them into a black hole?
That alone shows that the hyothetical "you" is the last person who should be allowed to moderate anything.
That one can only do it within reddit is of course merely a technical limitation. The idea can be implemented much more broadly.
If someone is doing that, it's classified as either a true threat or an incitement, both of which have been clearly established as not covered by the 1st amendment by SCOTUS and thus illegal - and can be stopped for no more reason than the fact that it's illegal.
On the other hand, online content moderation rules often get politically weaponized to silence dissent that is inconvenient but fully legal (and perfectly fine, for as much as you might disagree with it / hate that others get to hear ideas you don't like).
Going from "I voiced my opinion on the internet" to "people are inciting gassing the jews" is quite the stretch, crosses a well defined line, and is just nonsensical.