My two cents is that I would be surprised if there wasn't at least a minimal DVC representation at any resort they built offsite. I think the big difference between HI and DC is that HI announcement will help spur sales and is going to be majority DVC.....where I think the DC location will be primarily resort with smaller DVC representation. DC is likely to draw a different crowd from HI, lots of convention folks or non-DVC owners who might want visit the area and prefer the Disney themed resort.
Truth be told, it would be easy to sell HI timeshare, but more difficult to sell DC....there would be little home resort advantage, although I think some people would still buy it, just like some people will still buy HH and VB.