It's so frustrating that Ivy has yet to receive her comeuppance. I haven't forgotten the "Low" arc, and apparently no one else has, either. And the prequel to that traumatizing experience in HUSH RETURNS still has unresolved potential.
Eddie's a charming, intellectual fellow; but he can also be extremely wrathful. Would it make sense for him, as an egotist, to not directly address the problem of revenge against Ivy and Hush?
Also, I refuse to believe he doesn't recall those events. Coma or no coma, Eddie's always been crafty at misleading, and isn't it (currently at least) better for him to pretend he doesn't recall? Riddler's a genius, and he's clever enough to make a situation work for him. However, that being said, I'd hate to never see some resolution regarding those three.