It will probably surprise you coming from a company as impeccable as Activision Blizzard, but the final sprint of the development of Diablo 4 (which, let's remember, is still scheduled to be released on June 6), is going badly.
According to the Washington Post, the devs can't even imagine how the game will be released on the announced date without massive recourse to crunch. This while, since the beginning of the project, the management is dubious, the working conditions are difficult and the hours are harsh. Blizzard even had to resort to rattles full of stock options (I hear you can find them in nurseries in Neuilly) to encourage the devs not to quit before the game's release.
