I mostly agree with you, but Antifa has been around for a good minute. Of course I'm not saying the old group and the new group are completely related, but the 'old Antifa', the group which modern Antifa takes its inspiration, icons, symbols, etc from first formed in 1932 in Germany. That's one of the reasons why those dismissing them as 'just an idea' [to include the current POTUS] look fucking exceptional. They were organized then and they are organized now. Infact I would wager that Antifa is better organized than most of the militia groups [Three Percenters, Oathkeepers, etc] are, especially so in Portland. They have demonstrated their ability and resources quite well, especially last year, making it clear that they are an organized group likely with some form of hierarchy [even if it's just uppers to tell the lowers what to do] and while all the different 'cells' aren't necessarily in constant contact they do coordinate and cooperate.
That 'just an idea' shit and the notion that they're just some ragtag band of disorganized, exceptional tankies are lies to cover the asses of people who utilize them as attack dogs and finance their ops. Who you think those people are is up to you to decide. While BLM and Antifa most certainly cooperated in 2020, and both orgs are absolutely writhing with Marxist maggots, this guy is probably distinct from that. If anything I would throw him in the category of Black Panther/NFAC, with a side dish of that Hotep 'an evil scientist made white people in a lab we built da pyramids cuh' shit. All retards, but distinct flavors of exceptional individual.
Oh, and for the record, I doubt he was officially affiliated with any group. I'd peg him as a lone wolf type, inspired by those groups and their rhetoric but unaffiliated. If the rumors of two other individuals being in the car with him were true, or turn out to be true, then I would be more willing to consider that he may have been affiliated.