From what I'm hearing, it's a different ballgame than what you're thinking. See, each of those endings would make sense if this film was going in a direction where it was trying to solidy Batman's status as a legend/symbol, but that doesn't appear to be the case... per the film's slogan "the legend ends", Wayne is outed as Batman, and the symbol ceases to be. Gotham reaches a point where it "no longer needs Batman" quite literally, both as a symbol and as a living protector, which is what allows him to retire. Gotham is inspired by Wayne's sacrifice and decides to 'pick itself up', no need for lies or dramatic examples.
or, maybe, the "legend ends" means that batman no longer becomes a "legend" in gotham. he emerges. he becomes a recognized hero by the city. in those 8 years after TDK, Batman has just become a mythical legend in the city. no one knows if he still exists.