SMU seems like such an odd fit. Why not take Rice, Tulane & Tulsa while they're at it.
Odd for both conference and school.
At best, SMU's unlikely to be even top 10 in the DFW metroplex's supported programs, i.e., compared with UT, A&M, TTech, OU, OSU, LSU, Arkansas, and other massively bigger public universities with much larger alumni followings and non-alumni fan bases in DFW. Think BCU in Boston.
For the Newbie PAC #, media decision makers likely picked SMU as the least worst available as a 12th school. As marginal as SMU's success has been in recent decades, some possible considerations: PAC wants a a Texas recruiting spot, rapidly growing, increasingly wealthy DFW likely has large #s of PAC school alumni/fans, ridiculously affluent SMU alumni and a few decades+ of rapidly increasing California/western US student recruiting, and direct DFW flights for all but OU, OSU, and Wazzu. Repeat, media decision makers most likely picked SMU.
Challenging to think of much else to sort of rationalize Newbie PAC and SMU.