I'm surprised about the Batwoman thing -- they'd made a big deal about greater inclusion of LGBT characters in the last couple years, and various animated DC series had always included tongue-in-cheek references to various heroes not being 100% straight.
It's disappointing that DC apparently took that stance toward Batwoman -- although they apparently insist that it's just because they don't want a Bat-family superhero to have a happy personal life. But that seems like nonsense, because other characters have happy relationships. They also did the New-52 hard reboot of the entire superhero continuity right before "Gotham City Sirens" addressed the long-known-but-never-admitted relationship between Poison Ivy and Harley Quinn (which Bruce Timm of Batman the Animated Series fame will apparently acknowledge is a real thing, but won't make any official statements about it, probably due to DC).
And speaking of Harley Quinn, holy crap!
Absolutely tasteless in every conceivable way. Suicide is nothing to play around with or glamorize. Harley's always been a troubled character, but there'd be massive fallout if she actually gave into her demons and offed herself -- because she'd effectively be "losing" in her greater fight with herself and all her dependency issues. A bad example to comic readers, who are often teens, and thus going through some of the most emotional years of their lives. And that's not even going into the fact that she's a fan favorite.
Even if it was meant to purely be a shock-cover, something to get attention but would depict something that "only happened in a dream" or whatever, then it's still in bad taste.
Get your shit together, DC.