Harley's not COMPLETELY out of step, tho. The not talking? YES, that's definitely unlike the regular Harley we know.
However, there's still Harley we know in there. It's clear she's still in love with the Joker, she's still "playful" (her hair styles, her outfits, her grin when she takes out Harvey's goons) and she's still plays a lot of the roles she normally would in regular DCU when she's hooked up with him (girlfriend, criminal partner, tries not to upstage him, etc)