Sled,
I should have said strongly encouraged, not forced, but it is really semantics that you are talking about. Either you sign or you don't.
Last year there were a lot of cadets signing because they felt it would give them an edge, and historically for years the chance of getting rated was 90-95% nationally. This year with a 76% selection rate, many that were on the fence about going rated may not decide to risk it if they are concerned about that boards results.
Getting disenrolled as a 200 still gives you the chance of going into AROTC, however being disenrolled as a 300 basically closes that option off.