The Ada protects people with disabilities from discrimination in America. This should include military and post secondary education. Forgive me, OP did not state country of origin. Edit: the Ada allows exceptions for undue hardship. I suspect the military has an exception due to accommodations for certain roles being unable to be made for stuttering. But I’m just guessing. I don’t know the exact laws or legal cases but I would guess if people need an exemption form, the law is on the military’s side for disallowing PWS.