Blizzard has announced that Diablo Immortal will be launched sometime in H1 2022. The company states that it is improving the single and multiplayer aspects of the game, character progression, and a few other things, such as controller support.
https://www.notebookcheck.net/Diablo-Immortal-launch-date-pushed-back-to-H1-2022-controller-support-to-be-added-along-with-other-QoL-improvements-to-PvP-and-PvE.553322.0.html