Why would apple buy imgtech? Probably easier to keep hiring people as they come and possibly pay some royalties after legal battles. No need to take any baggage imgtech carries.
I wouldn't be surprised if apple gpu was nearing production at this time. Assuming imgtech gets paid per chip the imgtech announcements reads 24 months from now Apple pays for 0 chips from imgtech and all products have been migrated to apple ip. Following apples previous silicon cycle this would pretty much mean next iphone doesn't use imgtech or apple phases out next iphone and next soc pretty rapidly.
I don't read it like that, I read new products as meaning "new designs". Otherwise that would mean that in 24 months from today, Apple will not be selling any device that it sells today, which is possible, but not likely. Certainly it would dismiss the 15 month timeframe, I can't see the iphone7 disappearing totally by Aug 2018...or indeed the newly released ipad which is just hitting stores.