Being universal it would not be a disruption and no one would be "getting ahead" of his peers by going to school instead.
It would give us a population of young men who are all familiar with the military. Most of the resistance to the Draft was fear of the military as an unknown thing. With all familiar with it no combat or staffing draft would ever be necessary. A war situation would bring a flood of volunteers to serve just because the military is familiar to all young men, it is not a scary unknown and the training has given them character and confidence and instilled a sense of protecting family and country. The thing that undid the old Draft was its capriciousness and the opportunities for rich kids and politically connected kids to avoid it and stay cushily in universities. Make it a part of becoming an adult for boys.
I support the Volunteer Military concept 100%. So did Reagan. When our economy went bad in the early 1980's he opened the doors for enlistemnts and let volunteers join. When our nation was attacked following 9/11 neither Congress nor GW Bush called for troop strength increases. We need to do right by the military we now have. That should be the current GOP congressional priority. We as a nation have not been doing such since 1989.
I have a total of 8 years and two services. 4/2 Navy and 1/1 Army NG. All was volunteer obligations. I've seen enough to know that what you are proposiing would among other things be a strain on our already depleted military resources.
I support re-instating no gays, no women serving in combat units or zones, nor especially being allowed to be on combat ships.