First of, they said it is releasing for ps4 and Xbox one (probably will be out on next generation consoles, but they did not say that).
Second, they have not said anything about crossplay, pretty sure they said it is on their wish list or something like that, but as of now, it is not a supported feature in d4.
I will be on pc aswell, never got into console gaming.
If D4 is releasing a year or more AFTER the new consoles come out, there’s a 200% chance it’s being released on them. And consoles are... computers... just with a very simple operating system, it would be incredibly easy to cross-play between any PC and any console, which they said they want to do. Not sure why you even mentioned these things lol. But go team PC!
Just stating facts :-) I'm sure they will be out on next-gen consoles, but it's just not what is announced at this time.
Regarding crossplay, I wouldn't count on it, as far as I am aware, there is one game that supports this (modern warfare), and since it is not an announced feature, I just don't see them using time to implement it. Maybe in a future expansion or big patch, but I not counting on it for launch.