The Undertaker will be making an appearance at the Starrcast wrestling convention on May 25 in Las Vegas.
According to Dave Meltzer on Wrestling Observer Radio, there is “a lot of unhappiness” from Vince McMahon about Undertaker taking that booking.
Though Starrcast is not officially affiliated with AEW, it is seen as de facto related to them. Several AEW wrestlers will also be appearing there and the convention will be taking place on the same day and in the same city as Double or Nothing.
As of a couple of weeks ago, WWE had no plans for Undertaker at WrestleMania, but they are now talking about trying to get him on the show in some capacity.