I don't think it's dumb at all. Quite the opposite. Assuming Briles is more than content with staying at Baylor, what good would interviewing for UT and NOT being offered the job do him? Would only cause backlash and make him look like a douche to his current of prospective players. However, if he takes the stance that if offered the job (sans interview) then he will never have to live down trying to leave Baylor - he'll either NOT be offered or he'll bolt without having to answer to Baylor. Win/win in my book here.
Will admit, I've never been in the mix for a major college head coaching job, but I'd expect I'd need to interview for any job of that magnitude, not just be handed it. Really, I'd want to interview, if for no other reason than to get the measure of the people I'd be working for, especially in a minefield of a job like Texas.
I get the concern about word seeping out and then not getting the job. But if you ask all involved to be discreet, there are ways to avoid that. Saying "I'd take it if offered, but..." kind of sounds like something you say if you realize you're not a leading candidate. Not a good look.
Of course, all this is anonymous sourcing, so who knows who's really saying what.