While we wait for Diablo 4, we seem to be content with Diablo: Immortal, which will be released this year, it has been confirmed by Blizzard themselves.
Blizzard is currently alpha-testing Diablo: Immortal, which is probably needed given that this will be their first mobile game.
We do not know exactly how it went, but the question many have asked is whether the game will be released this year or whether it will take longer. Now Activision Blizzard has more or less confirmed when they talked about finances that the goal is to release Diablo: Immortal before 2021 is over.
However, there is no set date for when the game will be released, but technically, Blizzard has until December 31 to release the game as it looks now, but delays are nothing new to us.