Let's say that it's accepted. Content-wise, I try to avoid it if possible, but only because I don't think we have to care about it that much (currently). Like you wrote, FNV is set 50 years later and also the game mainly cares about New Vegas + the Dam, which is only visible on the very right side of our worldmap (the Dam isn't even visible).
About the caravan, I've added it some time ago, because I find it highly unlikely that nobody would send one to this place. I mean, seriously. The Hub, Boneyard, etc. are all in the NCR but Vegas is not? Even though Vegas is like the closest of all? Rather strange, but oh well... Anyway. The caravan isn't a government issued caravan. It starts from Shady Sands, but features no NCR soldiers (well, at least it shouldn't- I am not sure right now if this is the case).
Btw. yes, this stuff was added based on Van Buren. FNV wasn't released yet at this time.