50501 successfully organized the 50 state capitol protests the other day, and those got at least some news coverage. That was a good thing. If attending an event is unsuitable for you, there are other ways to resist. Me, I’m certainly already on more than one list, so being associated with a protest doesn’t change anything.
By comparison, I did some looking into a group called “American Opposition,” and my feeling about that is that it’s one small potatoes movie and TV actor trying to pull some sort of hustle.
In any event, I don’t believe you have to identify yourself to show up at a protest.
From the article you linked in your edit:
https://pol-rev.com/
They’ve been around since 2017. There’s surely a bunch more information about them than about 50501, and they’re “vouching” for 50501.