A couple days ago we talked about how Blizzard may be looking into doing cross-play for Diablo III now that the game is coming to the Nintendo Switch. Turns out, the person int he article misspoke about something that Blizzard has no intention of working on. Several outlets reached out to Blizzard to get a better comment on the situation, to which many of them received the same unfortunate news, which is that the company is not looking into cross-play for Diablo III at this time.
It's unfortunate, but let's be honest, people are looking for the next major game to bridge the gap between all systems after Fortnite and will take anything that even sounds like the possibility of news as gospel fact. Give it time, when we know about the next game, everyone will know.