The new release schedule is for D2R Items: Resurrected's upcoming content is set for April 14 to release patch 2.4 after which comes the Ladder's release will be two weeks after that in April. The delayed Ladder release should provide additional time to ensure the game's game state is set to compete in an environment.To be clear, Diablo 2: Resurrected's Ladder and patch 2.4 has never been officially announced as a date for release.
The third show-stopper, and the biggest problem that needed to be addressed, was that stashes could not properly switch to the new edition in Diablo 2: Resurrected. This kind of issue isn't going to be able to go live. Blizzard made the decision to put off the game to deal with it, as well as the database errors in order to avoid the risk of another diablo II resurrected items: Resurrected fiasco to launch the update and the update likely being removed anyway.