I'll wait...for a little while, lol. I really don't want to spend time messing with Insider Preview right now.
I feel the same way... I bought an official AT&T Branded (and still locked) 640 from Best Buy two days ago, because Upgrade Advisor was saying that my 635 1GB on Boost is ineligible for the update. =-[.
I was excited when Upgrade Advisor gave me message, "Good News. Your phone is eligible for upgrade. We are working with your phone operator to make the upgrade available for your phone", but I was very disappointed when I found out that I'd be sitting around waiting.. The other complicating thing for me is that the phone is unactivated. Anyone think this will impact my ability to receive the OTA update?
I was planning to use my 640 as a Windows 10 Mobile guinea pig, and if the water is good, switch carriers.
(Thanks for the suggestion in a separate thread, RumoredNow, to pick up an AT&T 640 and pop in a Cricket SIM... That's my gameplan, now that Sprint or whomever has blackballed my 635's upgrade...)