See that verb there? Thinking. Thinking that you can dictate the rules is not the same thing as being able to enforce those rules and you need to be able to enforce those rules in order to be an authoritarian of any kind.

That's not true at all, authoritarianism is a mindset, you can be the most powerless person in the world and if you believe that your 'superiors' should have the right to give orders and those orders should not be questioned, for example, you're an authoritarian.

Are there ways to enforce those rules? Yes, but you'll need to go into more detail as to how exactly that is taking place before you can accurately call it "authoritarianism".

Anybody who willingly agrees to follow the 'rules' and impose them on others is being authoritarian.

This is not a subjugation of free speech, this is a consequence of it. If there is indeed a swarm, and if that swarm does indeed have the clout to make others to capitulate to their demands, that leaves us with two options:

1.) That swarm constitutes the majority, therefore capitulation is democratic.

2.) The swam is NOT the majority, so either capitulation does not take place, or if it does, it is due to the swarm having the moral high ground (not being in the majority doesn't always mean you are wrong, of course).

It hardly takes a majority to browbeat someone into capitulating. It only takes a few dozen or hundred to make up a swarm, and people are likely to give up just to avoid the influx of hate and hostility. Look at Shirtgate, look at Donglegate, look at the incident with Tim Hunt. In all these cases majority sentiment was arguably with the victims of the swarm, at the very least it was only a few hundred involved in the attacks, and yet Matt Taylor was bullied into apologising, the Donglegate devs got fired and Tim Hunt got basically excommunicated from science.