He added that it takes about three to five years to fully roll out a new mobile generation.

It's been 5 years already. I'm sitting in my office right now at 36mbps and 200ms latency on 5g+. Meanwhile, if you go a mile north of me, you drop down to 4g and doing anything on the internet becomes impossible.
I'm pretty sure AT&T just changed the numbers from 4g to 5g and called it a day.