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.
I had another question. I saw that Sprint was selling the Oneplus on the website. The store told me I need to make changes to my plan and I cannot buy the phone outright. I have the family 1500 which is a very old plan. I don't want to make any changes to my current plan so I may not be able to buy the phone from Sprint.
If I buy the phone directly from oneplus I saw it said Verizon, t mobile and AT&T. Will this work for sprint too even though it is not listed on the site but says T mobile?