Oof. bitter pill to swallow hearing that a national seed is impossible and a regional host is basically impossible.
As another poster said, it doesn't take into account conference tournaments. Also, at least imo, depending on who it's against, Texas can bolster a host resume without winning all 13 of 13 games. Would probably take winning the conference though, or getting outright second and not being swept by Tech.
Also, and this is completely hypothetical as the odds are astronomical, but if Texas went 13-0 to end the season and finished 41-15 before the tournament (with a big 12 championship assuming Ok St doesn't win the remainder of their games either), I'd find it very hard to believe that Texas wouldn't get a national seed with that record and a road series sweep against Tech to boot. Then again, it's probably not best to deal in hypotheticals