Nobody brought up 'convincing threats of violence' before now. But since you did, yes, I'd absolutely claim a difference. It's one thing to fear being excluded from a group, and quite another to fear for your safety, whether there's an actual threat or simply something that feels ominous. And even when exclusion or banning is on the table, there's a step between quietly removing someone from a community (leaving them to make a scene or not) and loudly warning people about the threat they pose; it takes a lot more direct concern for others' safety to warrant the latter. And if you read the article, there were multiple incremental steps taken, and not everyone involved was ejected, nor does it sound like anyone was named who didn't want to be.

For that matter, exclusion is typically entirely reversible, given appropriate reasons to do so.

More importantly, however, you're focusing on the effect on the excluded, and ignoring their effect on others.

If you're asked to be quiet in a library, you're not being oppressed; even if you're talkative by nature, you can manage to shut up so others can ready and study. If you don't, you'll be asked to leave, or ultimately made to. But that doesn't mean people in the library go around with that fear and threat as the ultimate reason, any more than people go around with 'I might go to jail' as the only thing stopping them from injuring someone.

The same goes if you're participating in a community with a code of conduct that makes it welcoming and comfortable. Even if you're naturally toxic and obnoxious, hopefully you can manage to suppress that tendency in order to participate in the community. If not, you'll be asked to leave, or ultimately made to. But people participating in the community don't have that at the forefront of their minds all the time. That's largely the point.