I'm not sure MS would hold up releasing 2 flagship phones Worldwide just to pacify one US carrier which is #2 in the US?? I mean you walk into a AT&T store and its hard to even find where the Windows phones are, I might believe they'd hold up US releases but Worldwide?? Windows Phones have they're largest market share in other countries such as France and Italy, wouldn't be smart to **** off countries where they actually have a decent market share for the sake of AT&T who seems to care very little about windows phones.. Just my thoughts on the subject..
I really think the OS is the hold up... They want to dot all the i's and cross all the T's, they can't afford to release a buggy Windows Phone 10 OS disaster, it would shine badly on Windows 10 as a whole and right now Windows 10 is they're #1 concern..