Very unlikely there will be a DC date, or anywhere closer to DC than MSG. I'd be a happy camper if there were, and would go to both.. but I think the NA leg is complete with the dates you have seen, you're much closer to a new album than a show in the area IM(U0)O.
The biggest clue is that adding any date to the already announced dates would mean she'd have to play back to back, which she doesn't do anymore, or it would have to be after MSG also unlikely because she has another leg starting shortly after on another continent.
Though there is a six day gap between the last show in Europe (Glasgow) and the First in Canada (Toronto), but that also happens to be the same route that runs through Reykjavik a far more likely destination than anywhere around here.
In any case if you got Pit GA for MSG you'd have no trouble getting your money back for them.