The report pointed to new mobile plans such as the Verizon NEXT and AT&T EDGE, which allow customers to upgrade their smartphone early as one of the reasons Apple might move to this new strategy. Another reason proposed is that Apple wants to launch the iWatch with a brand new hardware:
That would point to the iPhone 7 and iPhone 6S both arriving next fall, with the 7 being the more expensive flagship model and the 6S being the mid range model from day one. But our source says that Apple is hesitant about launching the iWatch in the spring of 2015 without a new iPhone to go along with it, as it could give hesitant consumers an excuse to wait on buying both until the fall.
As such, Apple is looking at giving the iPhone 6S a release date in the spring with the Watch, and then launching the iPhone 7 in Sept 2015 accordingly. Another variant has the iPhone 6S arriving in the spring and sticking around for a full year, with the iPhone 7 being released in the spring of 2016. There is some precedent, as Apple only kept the iPad 3 on the market for six months before launching the iPad 4.[/su_quote]
Personally, I can’t see this happening for reasons too numerous to mention.