The fact that Harley says he hasn't used the giant balloons and henchmen in years is, imo, Dini's way of saying " Yeah, this is nothing like the Joker we've been seeing as of lately, he's gone classic here."
And quite honestly, knowing Joker's psycho ways, I wouldn't be surprised that he lapsed into this zany Dini-version when dealing with jealousy over Harley Quinn.
So yeah, no problem with this, they could have kept the bullet mark on his forehead but seriously, the Joker is the Joker in any incarnation, just kinda go with the flow.