One thing to think about in terms of double degree BA/MM (like Harvard/NEC) for composition. As a student’s music develops, he or she may want to have free choice about where to do a master’s, or, for that matter, directly enter a PHD. Doing a double degree locks a student in to a particular school 4+ years too early, in some ways.
The original poster may not have applied to any double degrees but a few of the schools listed do offer them.