Following Sony's Fortnite cross-platform announcement, Epic Games is working to promote cross-play with a new account merging system.
PlayStation finally gave into demand and pressure from competitors, announcing on September 26 that Fortnite on PS4 would be compatible for cross-platform gameplay, progression and commerce, starting that same day.
It marked a major shift in Sony's policy, having previously said it would never happen because "PS4 was the best place to play", and also completed the unification of Fortnite on every available platform.
To make the process of tracking all your Fortnite progression and purchases (cosmetic items, emotes, battle pass etc.) easier, Epic Games will be implementing a new merging feature.
Coming in November, account merging will allow you to link your PSN, Xbox account and Nintendo Switch account, all to a single Epic Games account.
This is mainly being done because of the many players who have created two or more accounts, in order to play on their different devices, before PS4 cross-platform was available.
1) An account-merging feature to combine Battle Royale purchases, coming in November.— Fortnite (@FortniteGame) September 26, 2018
2) Enabling unlinking a console from one Fortnite account, and relinking to another Fortnite account. Coming in a few days.
This account merging system should solve the other, and perhaps more pressing, issue that PS4 players had when Fortnite was released on Nintendo Switch.
The account locking which was in place on PS4, meant that if users wanted to play on their Switch too, they would have to start a fresh account - with none of their progress, skins or battle pass purchases transferring over.
Fortnite's free-to-play model with in-game purchases, and it's unique and rewarding progression system has likely been the biggest factor in forcing Sony's hand into allowing cross-play, and more importantly, cross-progression.