The Atheists make a good argument, at least to a point, but they are way late in the game to make it. Besides, no one even asked if those Seven were Christians. What if they were? That's the point where the Atheist's argument falls apart.
Brooklyn Borough President Marty Markowitz failed utterly to defend it with, "...believe me are in heaven for serving us so admirably." That's saying "Heaven exists because I sayso." FAIL.
The Atheists screwed up when they said "It's preachy", which it clearly is not, and in no way could be considered preachy to anyone of sound mind. But they really screwed the pooch when they said, "We’ve concluded as atheists there is no heaven and there’s no hell.” Which is just another "...because I sayso." FAIL
Saying there is no heaven, and saying with any certainty of fact, is awfully, awfully arrogant. But then again so is the reverse.
I do believe that The State, just like the rest of us, should have freedom of speech. They should be able to name the street anything they want. It's a proper noun, not a suggestion, same as St Marks Place and St Johns Place, both of which are in Brooklyn, as well.