Sony resisted cross-play for a long time, and before Fortnite players on the PlayStation 4 could only play with users
What is known
If you believe Wired, then Sony without a public announcementreleased cross play on the PlayStation 4 beta. This means that now the studio, which wants to make a multiplayer game, will be able to combine players with the Xbox One, Nintendo Switch and PS4.
Call of Duty: Modern Warfare will be the first project that will support common multiplayer at the start. In addition, on October 1, PUBG developers released a 4.3 update for consoles, and now the owners of the PS4 and Xbox One can fight against each other. Since Sony finished beta testing cross-play, there will be even more games with this feature.