Essentially, you won't have to spend money buying FIFA 21 again if you decide to upgrade to a next-gen console. EA has posted an official rundown of the new feature that will also be compatible with the publisher's other upcoming sports game, Madden NFL 21.
"If you purchase FIFA 21 for PlayStation 4 or Xbox One, you’ll be able to upgrade your copy once you have the corresponding next-generation console (PlayStation 4 to PlayStation 5, or Xbox One to Xbox Series X) at no extra cost by downloading it to your console up until the launch of FIFA 22."
If you buy a digital copy of FIFA 21 on either console, you're digital copy for the PS5 and Xbox Series X will be included with your copy on PS4 or Xbox One. You'll be able to download the game directly from the PlayStation or Microsoft Store on the next-gen consoles at no extra cost.
On the other hand, if you get a copy of the game on disc, you'll be able to download the game directly from the store on the new consoles, but you will need to put the disc into either console in order to download a digital copy of the game. It's worth bearing this in mind if you plan on getting the digital version of the PS5 with no disc tray.
Any progress you make or content you get in-game, including items, coins, FIFA points, players, match records, and leaderboard placements will also transfer over to the PS5 and Xbox Series X. Any progress in modes, including online seasons, co-op seasons, career mode and pro clubs will be specific to the console you're playing on, so that progression won't be carried over.
FIFA 21 is set to release on October 9, 2020, which isn't too far off from the arrival of the next-gen consoles, which are both still set to release in Holiday 2020.
Looking forward to getting onto the football pitch? Here are 7 things you need to know about the various FIFA 21 features.