https://www.theverge.com/2018/9/27/17911418/fortnite-sony-ps4-nintendo-switch-link-how-to-account-fix

Sony finally backed away from its staunch and hard-headed approach to cross-platform play yesterday, announcing that it would start letting players of Epic Games’ Fortnite use PlayStation-linked accounts on the Nintendo Switch and Xbox One, as well as play against one another on shared servers. The move is a huge win for consumers after the PR disaster Sony suffered back at E3. It may also be the first step in a broader, transformational shift in the console game industry away from the locked down and restricted approach to platforms that’s existed pretty much since the onset of widespread online multiplayers.

Still, it’s not exactly a simple solution, and Sony admitted as much when John Kodera, the president and global CEO of Sony Interactive Entertainment, said the feature would be available in open beta “to conduct thorough testing.” On the developer end, Epic is working to help players with a feature that merges accounts, so players with multiple purchases and virtual currency can bring all of that together into a single account. Epic is also working on a separate feature that lets you unlink an account from one device and re-link it with another. (The former is coming in November, and the latter in “a few days,” according to Epic.)