Holy balls, this again. As has been mentioned elsewhere in the thread, if Ford decides that the Raptor needs more power, it's a hell of a lot easier to upgrade the turbos/tune than it is to install/certify a whole different engine. Add in the fact that dealers who price their EB Raptors fairly aren't having trouble moving inventory, and it's difficult to believe that Ford would go to the trouble/expense.
IMO, even the Ram Rebel TRX wouldn't necessarily be a motivator... look at the Hellcat Charger and the Trackhawk... Ford doesn't have an answer for either of those vehicles, and seems to be just fine with that fact. The long and short of it is that the Raptor was designed to be a balanced package... engine, transmission, suspension, drive modes, etc... all complimenting one another to offer an overall solution that offers a driver experience like nothing else on the market. The GT is another example of this philosophy... it's certainly not the most powerful car on the market, and if I had to guess, Ford's position on that is ZFG (Zero ***** Given)... because the overall package works.