List of things I've seen done in/around Austin the last 20 years everyone said would never happen...
Built a pretty massive skyline including 4 new tallest, with the 5th under construction. Tallest building in Texas proposed, with a very legit chance to be built.
100+ miles of toll roads built. Billions of dollars approved to finally rebuild I-35 including tunneling through the central sections.
7 billion dollar light rail approved and funded, including downtown subway.
Cota, F1, MotoGP
Q2 Stadium, Austin FC
The population growth would continue to accelerate to the point that the metro now averages 50,000 or more new people every year.
I'm sure I've forgotten a bunch of other stuff, but I think my point is clear. Anyone doubting Austin is stuck in the past. This is a major city now, and there's not much at this point that could happen that should surprise anyone.
The next decade is going to put to bed any lingering doubts that lil ole Austin ain't just a big college town anymore.