I am certainly not an expert, but I have spoken with many MT faculty as a result of volunteering at a large regional college audition for several years. My understanding from those conversations, as well as from conversations with audition coaches and other experts, is that at most, or perhaps almost all, MT programs, artistic assessment will be independent of academic consideration. A few MT programs may consider academics when choosing between two or more applicants of similar type and talent. For most programs, its all about talent from the perspective of artistic admission.
You do have to pass a fairly high academic bar to be able to audition or be considered for admission to MT programs at schools with high academic standards for admission such as NYU, Michigan, UCLA, Illinois Wesleyan, Miami, Tulane, etc. The grand exception is CMU, which famously advertises that students do not have to meet high acadmic standards for admission to their acting and MT programs. Other schools with relatively high academic standards do admit students with academics below their typical standards based on high artistic merit.
NYU is often cited as a program that weighs both academics and artistic merit equally, which is, I think, an exception to the rule.