Nah, its not that they were trespassing. Its that they were trespassing while shouting that they were going to hang pence. It was because they were part of a group that attacked police officers. The goal of the trespassing counts.
https://www.reuters.com/legal/capitol-riot-defendants-face-u...
I’d hope, as I think you do, that those only guilty of association would find themselves exonerated.