Army Special forces have been doing small exercises like this for a long, long time. "Robin Sage" is one in NC. It's training unconventional warfare. Organizing the local populations to fight an insurgency etc.... Seriously doubt it's more then that.
Exercises often have multiple units participating, with different training objectives. There could be certain units that are training for some nefarious purpose - but the other units would not know. My opinion, maybe? - but if the powers that be want to use the military to suppress the population, they will need a really good pretext. And Army SF soldiers are not likely to go along with it (without some really, really good pretext). First, they tend to be patriots with stubborn ideals (you don't make it through training without being stubborn). Second, they tend to be above average intelligence; they are screened for intelligence and are required to learn a second language. Last, they tend to be a suspicious and conspiratorial group of individuals right from the start, not sure why - just appears to be true in my experience.