You should be able to tell if it’s a refueling plane based on the plane type:
https://en.wikipedia.org/wiki/List_of_United_States_military_aerial_refueling_aircraft
Air Mobility Command has a lot of missions, including airlift (transporting troops, supplies, and equipment), special operations missions, aeromedical evacuation, and refueling.
https://en.wikipedia.org/wiki/Air_Mobility_Command
The refuels that have been squawking this week have all been K35R type aircraft. Lower number in air and squawking were ~4 late in the evenings.. Largest I saw this week was up to 14 Wed/Thur - which would align with most of the troop movement of NG troops.
Of course those are the ones squawking and every refueler normally has fighter escort of some degree - which were not squawking.
I’ve just looked for the aircraft type for the most part.