What he really said in that 'we believe in generations' interview (you can google it) was that they were going to continue supporting PS4 during several years after PS5 release because most players were going to continue in PS4 during several years, and that he would like to see all their PS5 games using the next gen features such as haptic feedback, adaptative triggers, faster loadings, 3d audio etc. in PS5. What he said is what they did.
GoWR started its development in 2018, and HFW in 2017. Back then they didn't have PS5 devkits and they couldn't even know the PS5 specs because important parts of its hardware didn't exist back then.
So both games started as PS4 games. And after years of development later were adapted for PS5 too. It's literally impossible that both games could have started as PS5 only games and later they decided to make them crossgen. Timing of dates say that this conspiracy theory is wrong.