Tynion can't get into Harley's voice at all
Its fine if you just have her say jokes and act stupid if you are have next to no familiarity with her mindset.
Why would she want Joker dead? If she wanted Joker to die she would do it herself obviously. This is further pushed home by her own series. She wouldn't ask Batman to kill Joker either
This is a character who kills all the time why would she need someone else to kill for her?
Imo that moment probably should have went to someone like Jason or Babs
Having Harley deliver it seems too out of character because honestly why would she care about Gotham being destroyed or the people who are dying? There's no connection there for her
In fact you could probably replace Harley entirely this arc with Selina and I see very little changing.
This is one of those times where you can tell someone is just stuffing Harley Quinn into moments that just don't fit the character and I'm saying that as a huge fan mind you.
And they just left Punchline tied up to escape. There's nobody smart in this arc in the previous arc Bruce at least made the effort to lock up Deathstroke, Cheshire, and co