@Cro_Pittt Even without back compat, you're data is stored on both your account and in cloud (sony and respawn servers).
This is not so much a cross progression thing as a carryon like you accurately mentioned Cro. If they dont immediately have apex carry over to next gen the back compat kicks in and pulls your info from the cloud.
So stop worrying ppl. The fifa deal is that moneys at stake so they want you to pay again to experience fifa with next gen technology instead of current gen technology (basically using a ps4 emulator on ps5 to play the old school fifa most likely)