I was planning on buying my friends iPhone 6 but it is locked to AT&T. I'm going to get it unlocked via a third party but the problem is I'm on T-mobile right now, so it will work, but in a couples of months I will be switching over to Verizon. I was wondering is the iPhone 6 from AT&T still CDMA unlocked? I know Verizon will not "activate" the phone on their side but if I get an activated sim card from them it should work correct?