I have no faith in them, at all.
D3 was a train wreck, and including focused on straight action and no RPG making the game feel like it was Goldenaxe with a Diablo skin, while it was fun on consoles, and a fun game it sure wasn't and didn't feel Diablo game.
Diablo as a franchise was successful and legendary because of it's marriage of turn based RPGs and an Action game. The problem is Blizzard seems content with reinventing the wheel rather than giving the actual fans of the franchise what they want.
Diablo 4 was apparently more a Dark souls clone in early development, no one ever asked for that, sure cool, but that isn't Diablo. Why can't they just make what the fans want An ARPG inst ad of another action game skinned and dresses to look like one, If I want to play Dark Souls I'll play that If I want a fantasy brawler I'll play Gauntlet, Goldenaxe, or D&D Chronicles of Mystara.
Just give the fans what they want a Diablo ARPG. D3 sold on the expectations it was like D1 and D2 which it wasn't to the point it doesn't even qualify in the genre. D3 may have been a financial success but it was far from being a critical success that they needed to produce.
GGG spawned because of the incompetence.and created Path of Exile, which every person I played or know who played D1and D2 agrees is the new Diablo series and a shining example of how to make a F2P game properly.