There is unlikely to be a large scale mutiny. The US in Vietnam never got to the point of France in 1917 where there was already, what a million dead and millions more wounded? The US had 58,000+ dead and 300,000 wounded. That is a magnitude less.
It takes a lot to ruin a modern army, and the US hadn't reached that state yet. When real damage started being done in the military as a result of the war, it was when everyone knew the US was going to pull out without winning the war and morale plummetted (because no one wants to be the last guy killed in a defeat).
At best, you might have several small mutinees in protest of idiotic commands which would cause great scandal and cause a reevaluation of the conduct of the war.