Re: Joseph Gordon-Levitt as John Blake VI
I don't think they didn't call him Dick Grayson because the audience wouldn't get it. I mean they could have called him Grayson the entire film and just reveal that his first name was Robin at the end the same way f they wanted to
I think they instead just wanted an amalgamation of the multiple robins which play such a big part of the comics. John is Dick's middle name, and Blake is reminiscent of Drake. Plus all the hothead references.
I don't see the big deal with a 'made up' Robin either. Miller did it in TDKR.