Since PC, Playstation and XBox are all handled by different companies, that almost certainly will never happen.
Microsoft and Sony don't handle the games that are made on their support, unless it's a game published by Microsoft or Sony. Unless you're saying Diablo 4 will have a different studio developing each version which I really don't think it will.
As an example, a game I'm really looking forward to is Dungeon Defenders: Awakened and it will have cross-saves for PC, Switch, Ps4, Xbox1.
Character importing wouldn't be that hard to implement with Diablo 4 but I doubt they'd care enough to do it. You could simply be able to log-in to your battle.net account on consoles and Import/export your save. Although, it would require the game versions to be the exact same.
I believe they are talking about Xbox Live and Playstation +. Sony has been Notorious for not allowing Cross play.
I believe they are talking about Xbox Live and Playstation +. Sony has been Notorious for not allowing Cross play.
https://www.deviantart.com/aerisot