Because it was possible to play it off as a pet name. The bleeping things out is to make you go, "OH! Thats why he called her Kiddo, its her name, not just a pet name." If they bleeped it out, people would be just confused when her name is revealed and they would see the bleeping as pointless since her name didn't really matter storywise.
It's possible, but since QT left it out, I doubt it was a vital piece of information. I mean, there was a bit that Nice Guy Eddit says in Reservoir Dogs about a nice black nurse he knows named Bonnie... I think he just has ideas in his head. Who knows - maybe B.B. Gunn will be a character in a nother movie - like Bonnie.
I wonder if the falling-out between Budd and Bill will be covered? One thing I really wanted to see was the actual scene IN the chapel - for the simple reason that it would have given us some clue as to Budd's area of expertise. Notice when they all approach that he's the only one bothering to hide his gun - so maybe, as I've thought all along, he's the instinct man.