100%Well...it just means youre an anti fascist who happens to turn up in person to oppose nazis. Its like pretending vegetarians are a group who communicate and organise. Sure you'll have friends who go to protests with you ans you'll go to workshops on direct action sometimes but its not an organisation thing. I guess similar to anonymous but i imagine less communication than anonymous has with each other. Anonymous seems a bit more time consuming than spending a couple hours a year protesting nazis.
to add on for others bc I know you know,
there are other related groups that are more group-y but usually their focus is something else, like unions/organizing, or food not bombs, or other mutual aid orgs, etc.
people have been labeling anyone who shows up in black bloc gear "antifa," but black bloc is just one tactic and while it's often utilized by antifascist protesters, it's not unique to them.
the only really long-term antifa organizing kinda thing if you could really call it that is in the form of tracking and documenting fascist activity.