The change would almost certainly not be a reversion to older, inferior technology. The four layer technology was instituted to solve a particular problem. Fuji has probably found a way, most likely a superior way, to solve or avoid the problem using three layer technology. (Note that "three layer technology" may actually be something between five and ten layers.) Research into color negative film technology seems to be very active, and the quality of the product technology is increasing. But the drive to make new and better color negative films is based on competitive pressure and customer demand. Right now, the market for these films is pretty good. If it declines, R&D will fall off.
Originally Posted by B&Wpositive