My son just graduated from Michigan and had no professional experience unless you count an episode of iCarly when he was 13! 
My daughter has a male friend who was in her local regional summer program. He is going into his junior year at Michigan. No national professional experience that I know of; however, he is very attractive.
I don’t think you need national professional experience to go to U of Michigan’s MT program. Or even to CMU’s program.
However, I think it is fairly rare at either of those two MT programs for students to gain acceptance who have no training or experience. Those whom I know who were admitted, had training and experience and were not diamonds in the rough. That is true of quite a number of BFA in MT programs these days in fact. Some have more experience or training than others, but those with none in any of the three skill areas, particularly girls, have a MUCH tougher time getting into a BFA in MT program in this day and age. Same could be said for flute and piano players or VP majors.
I don’t think anyone said showbiz (or life) was fair…
I personally know quite a few people who have been in national tours or Broadway shows as children or young teens who pursued/are pursuing/want to pursue a degree in acting or musical theatre. That’s the national experience to which I was referring. Maybe those who tour or get on Broadway as juniors or seniors in high school don’t feel the need to get a degree in it; I could see that being the case. We all have heard of people who have taken off a year or two of college or have never gone back after landing spots in national shows during college.
My point in post 65 was not the emphasis on tougher odds for females to gain admission. My point was ANYONE with NO training or experience in the 3 main MT skill sets applying to BFA in MT programs is going to have a tough time against the many who are vying for a slot who do have training and/or experience.
Also, like @myloves I know plenty of people who have gone onto BFA programs who have had professional experience, often on national level, and sometimes at the highest levels like Broadway or feature films. They still want a college education and further training.