Game publisher EA just recently confirmed that the next games to be introduced can be upgraded for free for next generation consoles.
EA will allow free upgrades for next gen consoles
Electronic Arts COO Blake Jorgensen recently talked in an earnings call to shareholders and press. One of his mentions revealed that this year the phasing will include the effect of revenue recognition from games that they are launching for the current generation of consoles that can also be upgraded free for the next generation.
This line alone basically means those who buy their games in the future when the next generation consoles arrive and they have them, they can just easily transfer their games and upgrade them there to be playable. PlayStation 5 and Xbox Series X did reveal that they have the capability of backwards compatibility with the PS5 only compatible with the PlayStation 4. Xbox, however, did reveal the Smart Delivery system, so there is that possibility as well. Currently, there is no confirmation on both sides. It would be nice to have this feature on both sides though.