Historically, the soldiers themselves rarely mutiny unless one of two things happen:
1) Their pay goes into severe arrears / the state goes bankrupt, or living conditions for the specific soldiers in a location go beyond physical limits of what's tolerable
2) There are existing ethnic or religious divisions with active political conflict ongoing outside the military
Mutinies used to be extremely common in armies, the norm even, but modern states will usually spare no expense (or hold back on political purges) to prevent mutinies. How far up the officer hierarchy a mutiny goes and to what extent it is aligned with other political events could be used to distinguish them from other things like open rebellion or revolution, but these are essentially "bottom up" events.
If the unrest starts at the top with senior officers, it's a coup, not a rebellion. Whether a coup works or not depends on many things, but mostly it's the timing and the degree to which the senior officers are on board that matters. The body of the army in a successful coup won't have time to hear what's going on, let alone decide what they want to do, while ideally there also wouldn't be any loyal senior officers in a position to impede it long enough for word to get out.
Edit: Anyway, the gist is that if the US military were to oust Trump, it would almost definitely be a coup carried out by the senior officers and not have any connection to the "loyalty" of the army itself.