I always suspected this generation is the first where stop gap iterations will actually be viable. Not Native 4k (although that will be possible+the marketing gimmick), but 1080p (or slightly higher)+60fps+Improved effects and graphics. Maybe a few games natively 4k/30fps (Indies, remasters etc).
I think this gen sony is the only looking at it, MS and Nintendo will both have rebanded systems out in the next 3 years.