You will find that there are plenty of students in college MT programs (maybe even most) that are light on the acting training. But they won’t all be and those that enter with acting training will stand out in that discipline the same way the highly trained dancer will in dance. I sent my MT off to college more than anything else with strong acting training. It continues to be a strength for her today that has opened doors.
But when training begins matters more in dance. You can work your butt off in dance in college, but chances are you will never catch a talented MT who enters college as a highly-trained dancer. I’ll concede that. So though it makes me cringe to say so @lovetoact and it probably makes you cringe to hear it since you also have two kids on the BFA acting track, that advice about dance for your HS freshman son is pretty good especially if you have to triage which most of us find we do. That’s not a bad age (for a boy especially) to get going with the dance in earnest. I’ve also got a college senior awaiting graduation in a BFA MT track and I can tell you the males who stand out as dancers (all else being equal) get work.
Note that I didn’t mention anything about vocal training. It’s MUSICAL Theatre. I sort of take that as a given. Shout out to @MTTwinsinCA above, @SoozieVT and others whom were also smart enough or randomly lucky enough to be sure their kids could play the piano. GREAT SKILL to start early. Huge asset in this business.