With the introduction of DCC and the push to get BOLC done before you graduate, then you are absolutely right that it's going to interfere with your study time for boards. It used to be that BOLC could be deferred until intern year, maybe later depending on the situation, with the understanding that you wouldn't make O4 without it. This doesn't seem to be the case any more.
I didn't go to DCC so I can't speak with too much knowledge here, but from what I understand it's intended to give new recruits a taste of the Army side of the house, like how to wear your uniform, how to fire off a crisp salute, what the rank insignias mean, etc. That used to be covered in BOLC, but whatever. Rest assured that both DCC and BOLC will do absolutely nothing to make you a better physician, and if Big Army is insistent that DCC and BOLC be completed after MS1 and 2 respectively, it will actively work against you.
I don't know what the chances are of you deferring BOLC but the justification of getting more study time won't fly. EVERY student wants that and they're not going to defer an entire class.
What you need to understand is that DCC is the brainchild of some O6 and their high-ranking cronies who need to put a bullet-point on their OER so they concocted this scheme as a way of making it look like they are grooming future Army leaders when in fact they are actually pissing them off, wasting their time, and harming their medical career. When in medical school, your #1 goal should be to do well in your classes, learn as much as you can in your clinicals, and pass your boards with as high a score as you can muster. When you graduate and complete residency you will get additional training prior to a deployment, like how to wear MOPP gear, don JLIST, wear armor, etc. There is absolutely no reason to interrupt medical training to do this in med school outside of the summer following MS1, although I would argue that trying to get in on a research project is a better use of your time. The Army Medical Corps was founded on 27 July 1775, and in the past 242 years the vast majority of physicians that put on a uniform had no prior military training. Oddly, Army Medicine or the war effort did not grind to a halt because of this inexperience. DCC is a pointless hinderance and the Army will likely realize it made a mistake in about 5 years when boards scores start dropping. When you sign up with HPSP or USUHS, you surrender control over lots of things. Apparently, you now surrender control over board studying too.
Have you already signed?
