To answer your question though:
D4 has Cross device progress, but not a shared license. You would need to buy D4 (and any expansion) on each platform you wish to play it on (Playstation, Xbox, PC, etc.) Then you would link those platforms to your Battlenet account so that all of them share the same Battlenet account progress.
Same goes for Battlenet accounts. Each Battlenet account would need its own copy of any Blizzard game. Licenses can not be transferred between Bnet accounts.