https://wccftech.com/diablo-iii-cross-play/

Diablo III is hitting Nintendo Switch next month as Diablo III: Eternal Collection, marking the seventh time the game has been released on different platforms. Cross-platform play is not a thing for any of these versions, but it seems like things will change in the future.

At a recently Diablo III: Eternal Collection preview event, Business Insider has been told that cross-platform play is in the works and will definitely happen. The Blizzard representative stated that it’s not a question of if, but when, and the team is working with both Sony and Microsoft to allow cross-platform play with the Nintendo Switch release.