Your point is only half valid. You said he made changes to characters and cited Dick Grayson and Henri Ducard. Two characters that never appeared, Ducard however, at least got a nod.
Now for example, if he had Dick Grayson actually appear in the film and he never became Nightwing, I would see your point. But he never appeared.
Everybody became a close approximation to their counterparts.
Now, if Thea becomes a red and yellow archer called "Speedy" I'd consider that a John Blake situation. Not Ra's Al Ghul, because he was always Ra's Al Ghul. Dinah's situation doesn't apply here.