If Ford releases a 2021 Raptor, then they must have another powertrain in the works to come after the TRX is released. No way they are going to release something new now and let Ram have the last say. The new generation F150 will be around for another five years (give or take). That is a long time to leave the Raptor unchanged after the Gen 2 went through very small changes over its production cycle.
I also think it is a little much for them to release the new F150, Bronco, and Raptor all within a year. But maybe because of COVID-19, they are putting all their chips on the table. We shall see.