Makes a fair bit of sense to me. It's involving many of the same factions and in a manner that would actually make sense instead of just dragging them all the whole way across the continent. NV is just barely North East of where the first two games took place, there could conceivably be a decent number of characters from Fallout 2 present in New Vegas. Harold would have made far more sense in NV then in DC.
You have a point. BUT, the reason I questioned it is because we don't know that much about the game. The only thing connecting it to the first two are two (confirmed) factions, and the fact that it's on the same side of the country. I'd say it's pretty early to say "This has more to do with the first two."
Your hot dog example is a straw man fallacy by the way. You have made a much easier to attack position than the one actually represented. Of course hot dog vendors don't have more to do with the first two purely because it's on the west coast, but that is entirely beside the point.
That's what you get when you try to make a quick point without thinking about it.