No. Just no. Tyrael's plan was shit to begin with, and now Blizzard goes "Oh, but there's another angel, only this one happens to be Death, and he wants Diablo back because Diablo kills people and that means moar powah for Death!"
I swear - they used to be terrific game designers and okay writers, but now they're turning into meh designers and horrible writers that seemingly come up with over-produced fanfiction, more than anything else.
I'm guessing the one big purchase hook will be that they're bringing Necromancers back - but I don't care anymore. The Witch Doctor was a poor replacement, but I don't care.
Here, have a lavishly produced and super-dumb CGI animation: