The 68RFE is not an option, but the manual still is. When I started looking for a replacement for my F250, I kept my options open for different class trucks and manufacturers. I needed payload beyond Class 3 pickups, so that eliminated the 68RFE (as well as GM trucks). My original intention was actually to go back to a gasser due to the cost and complexity of today's diesels, but realized I would be limiting myself too much with short term savings which could have resulted in swapping out prematurely also due to those limitations.
I understand why FCA offers the 68RFE and it may make sense for the lighter or occasional duty haulers, but this current truck of mine is dedicated for hauling and towing.
I understand less why FCA does not upgrade their manual transmission. Although they have following, the limitations are creating attrition within the manual crowd to a point where it will be dropped.