So... I can get why the first trailer for Birds of Prey focuses pretty much completely on Harley Quinn. She's the mainstream darling and they want to draw in as many people as possible to watch this and they'll probably/hopefully give the titular team more attention in future promotions. It doesn't really gain my interest any more than it did before but I get it.
However, spoilers:end of spoilers
in one of the final scenes Harley has little Cassandra Cain throw a stick of dynamite out a window during a car chase and it probably kills a bunch of people. Like Cass is most likely completely unaware of what's going on in the chaos and we don't stay long enough to see Cassandra's proper reaction. But having Cassandra Cain just kill people like that makes me very wary about how they'll handle her character in the movie.