i've seen this a lot around here too with permits not being pulled. several years ago i could check permit reports and have an idea of when upgrades might be starting. i don't know if cities have just relaxed on tower permits or they don't record them anymore or if t-mobile just isn't following the "rules" when it comes to permits, but most of the B71 upgrades that have happened around here over the past year i haven't seen permits for.
Following up on myself, my wife and I ventured to Wegmans for the first time since March this morning. The T-Mobile rack at Hayfield now has a fourth antenna, that resembles (but is taller than) the Sprint Massive MIMO antenna on the rack below it. Guessing this is the n41 gear.
Oddly, I checked for permits, and there's only electrical permits, and no antenna replacement/addition permit. Not sure what to make of that.
So here's my crazy prediction:
I believe they'll wait that long to ensure that basically all of AT&T's customers will have phones capable of doing LTE in CLR, and WCW's customers will all be VoLTE capable. In addition to the obvious "acquire one company at a time" thing, even though WCW is tiny in comparison with Sprint.
You need to be concerned with TMobile going forward and not Sprint. That brand is obviously being killed so there is nothing to worry about. If rumor pans out, the Sprint brand will be all but retired on August 2nd. You're a TMobile customer now. We all are.