See SenorZ’s post above. Their main gym has 24 rows of seats along each side, easily capacity to seat their whole student body. That’s enough for even a 50 team event. Plus, as the same source points out, they have three gyms, which means you have the two auxiliary gyms for pit space, which is plenty even at 10x10 pits. As I said to begin with, this is a very wealthy and highly rated school that has no problems pouring money into facilities, which they have. I’m from Memphis originally and still have family there, so the nature of this school wasn’t exactly unknown to me.
By the way, teams may not like 8x8 pits, but they’ve been used more than once here in NC District when smaller high schools have hosted. We usually limit our district events to 32 teams because most of the host schools (and it’s almost always high schools here, except for the NCDCMP which is at a Campbell Univ) don’t have the capacity for larger events, since there are very few that are the size of a school like Collierville. Even my own school, in a very wealthy district (Chapel Hill-Carrboro) is only 1600 students and has a mere two gyms. The events pretty much have to be at high schools though, because arenas and colleges are tied up that time of year with basketball and you just don’t mess with basketball season in NC.