That's the most likely, outside of just regular old bait. It's the left's version of fedposting.
Antifa doesn't have the numbers to spark uprisings across the country. They've been frozen out of pEaCeFuL pROtEstS for the last 2 weeks, and they got kicked out of CHAZ in the first days. They get beat up by proud boys and bikers whenever someone bothers to show up and oppose them.
I don't think the cops are going to be up for letting a historical site get destroyed on July 4th. If you sent an entire city's chapter to Gettysburg to desecrate it, they're going to be bopped by cops. If the JBGC shows up, they aren't going to make for sympathetic photo ops.
It's always possible that randos fuck around and wind up finding out, on either side. But we've already had shootings at "protests" and nothing happened--the Hispanic guy in Seattle, the guy in Albuquerque, the daily murder at CHOP. It would have to be some kind of mass shooting bloodbath to get any lasting attention, and I don't think either side has the appetite for that.
Better than the fugly witches casting hexes.