People were also charged for coordinating and supporting J6 without being there, e.g. Enrique Tarrio of the "Proud Boys" was charged with seditious conspiracy based on activity in messaging apps. If people in these Signal chats were aware that people were using force to inhibit federal law enforcement, which some of the leaked training materials suggest is most likely true and easy to prove, and there are messages showing their support or coordination of those actions, I assume they could face the same charges.

They had a lot more than metadata on Enrique Tarrio.