They also no longer sell Huawei devices to their customers.
The latter is likely tied to their accusations of industrial espionage and theft by Huawei employees: Possibly paywallled NYT article.
So there's no love lost between the two companies.
Wifi can only augment service. It's too short range, too inefficient, and too balkanized. Indoors the access points are all stepping on top of each other and while Passport 2.0 will improve authentication it does nothing for handoffs and the other issues.
Indoor LTE promises to be spectrally efficient, relatively easy to deploy, and cost effective (each access point covers enough area/devices to be worth the cost/effort.) They're been widely seen as the solution for local cellular 'infill' - now they're going indoors.
Remember cell towers typically radiate downward at an angle, in an umbrella pattern. Therefore a locally dense area requires three or more millionish-US$-each towers around it. Or a thousand plus wifi access points, every 20m-50m, all requiring backhaul. Or a dozen ~US$50,000 indoor microsites offering LTE. They start to look very, very, attractive.
As to Wifi being removed from handsets, that is tremendously unlikely. Offloading heavy domestic data usage to another medium is still preferable. Corporate customers would flat out refuse any such handsets. And consumers would be rightfully incensed. Nobody (well, Verizon might try merely on their maximum-evil premise) would go for that.
T-Mo TOS don't appear to allow tethering to 3G. They do allow tethering on Edge at no additional charge (so back down your device.) Their happy helpful customer support (really, I think they pump drugs into their air) will happily walk you through tethering on a BlackBerry, no additional cost. Tho >10GB in a billing cycle you get throttled.
That said T-Mo plans are cheapest, win JD Powers for service, are great about supporting random phones, coverage has improved considerably in the past few years, and T-Mo does lead on Android.
Earth is a beta site.