I see no mass exit from diesels but their is an interest resurge in large gas truck engines. And rightfully so with the senseless without merit rules of some of the current government regulations on diesels. Not everyone can do even just a clean tune & EGR shut off. Plus the gassers make good sense for some trucks duty cycle.
The 7.0 (426) would not be a whole new engine merely taking full normal advantage of what the existing block has to offer. And yes to stay on par with the new ford & GM gassers & 10 speed transmission.
Ram has already done the first smart & important part in offering the excellent 8 speed in 19 Hemi powered HDs. I’ve mentioned it before but I now have over 550,000 miles towing TTs on that transmission behind more torque than the 6.4 puts out with no repairs. It should be a great improvement in the truck. Gear stepping, durability, mileage, acceleration, and minimal gear hunting with a quick firm shift.