Cthulhunicron said:
A - If the first fragment doesn’t match any known records, then at least the parts of Artoo’s map (if not the entire thing) surrounding that gap would also have to be uncharted. It’s like saying “we have a map of the United States, but there’s a mysterious gap between Utah and Kansas.”

I don’t think that analogy really works. The gap between star systems is exponentially bigger than the size of the gap between Utah and Kansas. Unless you know exactly where that star system is you’re probably going to miss it if you go into that uncharted territory blind.

C - If Artoo has been shut down since Luke left, how can he be in possession of a map tracking his journey? Furthermore, if he had the map this whole time, why didn’t he tell anyone? Sure, it wouldn’t give Luke’s precise location, but they would still be given a major clue. Going back to my US map analogy, you wouldn’t have Colorado mapped out, but you at least know he’d be between Utah and Kansas.

These are good questions and I’m thinking perhaps it may be tied to Rey being present but I don’t even believe that with strong conviction.