Earlier quoted context omitted.
It's all publicly funded universities in Texas, not just the UT system. In other words: you've just pissed off a lot of Aggies grouping them in with, ahem, tu.
No one in Texas calls it “TU”. Rather, UT.
They do that to imply that "varsity" is not the University _of_ Texas.
As with lots of things coming from College Station, you just sort of have to accept it.