The EA Play event, showcased many games, including FIFA 21 although we didn't get a lot of information.
EA took to their site to answer the questions everyone had.
Will My Progress On PlayStation 4 And Xbox One Carry Over To PlayStation 5 And Xbox Series X?
All the progress that you make including players, items, coins, FIFA points, match records, and leaderboard placements, as well as progression in VOLTA Football, will transfer from your previous console to the next-gen and back again.
Meaning all data from your Playstation 4 or Xbox One will transfer to your PlayStation 5 or Xbox Series X.
On the other hand, all progress in modes like Online Seasons, Co-Op Seasons, Career Mode, Pro Clubs, etc will be specific to the console you play it on and will not transfer.