All platforms are shared games?

Yes, you can find it on blizzard official site and on 14747743882 topics here

This post was edited by KniGhT_SP on Aug 1 2021 02:06am

Last I heard it's cross progression, which means you can play the same characters on your account across all the supported devices you own, but you can only join games and play with people who are on the same device as you are at the time.

No.
But.....
If you decide to play through battlnet (you will be asked if you want to play on battlenet on consoles)
You can then access the same battlenet characters on any platform (as long as you own a copy of the game on that system/console)

/Thread