They should have quietly announced Diablo Immortal before Blizzcon because it's clear to anyone this wasn't going to go down well with fans. Or done what Bethesda did with the Elder Scrolls mobile game, announce Immortal early first and then at the end just show a screen with "Diablo 4 in development" and everyone would go away excited and they could push their mobile game all they like.
I mean why they thought this would get a positive reception from PC gamers who adore this historic PC franchise is beyond belief. I'm not the biggest fan, I dabbled with the franchise in the past to a degree but never got super into it, but even I knew fans have been crying out for Diablo 4 (D3 came out in 2012,) so their handling of this game as the "big super exciting reveal" is the definition of tone-deaf. And as said above, I personally hope it crashes and they cancel it early because it can ONLY harm the franchise as some say the dumbing down in Diablo 3 has already done.