I am specially talking about the big scene with final performances of Kevin Conroy as Batman and Mark Hamill as Joker. I saw the scene on YouTube and I thought it was amazing.
Kevin's final performance was much better than Suicide Squad: Kill the Justice League (at least for the moment). That's not the controversy here.
The controversy is apparently Mark Hamill's final performance as Joker. He reprised his role as the DCAU Joker. People have said it was a different actor, but this is clearly Mark Hamill as Joker. The dude is in his 70s and he was trying to go back what he sound like when he was in his 40s (the first couple of seasons of Batman: The Animated Series). That was the most impressive out that scene (other than Kevin's final words as Batman). What I'm trying to say is that was clearly Mark Hamill as Joker and there was no way he was going to let another actor replace him for this final performance before he retired as the character. If that was the case, it would've ruined both Kevin and Mark's legacies as both Batman and Joker.