Given what they were going for (I mean the whole movie wasn't ever trying to be subtle) I honestly don't think that would have been enough. That wasn't a subtle moment of fan service like referencing Killer Croc, that was big blatant "HERE'S WHAT'S HAPPENING" stuff.
I will say, I think Robin is one of the worst characters in comics, and I would 100% watch a JGL Robin movie.
JGL is quietly putting together a nice little resume of films. I liked Brick very much and LOVED "The Lookout".
I mean I'm not a comic book nerd at all; never even read a single Batman comic. I don't think I've seen any Batman movies outside of the Nolan films and some PG animated film I saw when I was 8 or something (Mr. Freeze was in it).
Still I know who Dick Grayson is ffs. Didn't know it was that esoteric. (For example I have no idea who Killer Croc is)