I told USNA that I was a recipient of an Army ROTC scholarship and am in fact in College now as a contracted cadet. They viewed it very positively and I believe it shows true dedication to wanting to serve regardless of the path you take and wanting to become the best officer you can. Whether, or not you tell them probably won't make the world of difference for you, but it definitely cannot hurt.
USMC8
USNA 2017 Appointee