When we can't assume one or the other we have to look at something else where we might reach a conclusion. If someone says they are oppressed we can look at what would hinder their oppression. Arguably this would be things like transparency, participation and equality. As those things make oppression harder.
So if someone says they are being silenced a reasonable person might look if there are multiple known moderators who can check each other, a moderation log to see how moderation is happening or some voting system to reflect the opinions of the community.
In most cases where people are says they are being silenced these things doesn't exist. As such it would be unreasonable to dismiss their opinion as there seems to be an argument for the restrictions not being legitimate. Otherwise you just create a different cesspool of unreasonable people.
Presumably you disagree, but then you disagree with the far majority of well regarded implementations in the real world. I am about to buy an apartment and it is the same thing. You need a witness, a contract and approval from the housing organization. Because that how you reasonably decide what happened.
And yes, people break the news all the time. For example on Twitter on this very post. That is the point. When they do how do you know who is reasonable? Which is what I have argued.
We're at least a couple decades beyond the point where a reasonable person could possibly entertain such a thought. Lack of restrictions always turns communities into cesspools. They don't necessarily die, but the people that hang out there are the ones that enjoy spending time in cesspools, and that's usually different from the vision the creator of the site had in mind.