Glad to hear T-Mo is going to [finally] allow this on UA - sometime.
For just about ever - ok - maybe the last 5-10 years, they’ve offered the hour free wifi on domestic carriers (those using GoGo) - but UA was always excluded. I suspect they’re launching the new program on AA, DL and Alaska first since they already work with them, and will probably take time to get everything set up and tested for use with UA.