Fans didn’t get to see Harley at all, and the closest that the show came to hinting at it was with the very act of electrocuting Barbara, since not only was the character previously rumored to take on the bat-swinging villain’s persona, but several of Harley’s comic backstories have featured electrocution in them.
Plus, isn’t it somewhat strange that David Mahzouz is offering up would-be spoilers for Babs’ survival — during a panel at the Heroes and Villains Fan Fest (via ComicBook.com) –after already offering up quasi-false spoilers in the middle of Season 3 about Harley Quinn showing up in the big finale?