Interesting question : I wonder who will choose to play Washington indeed, it will get interesting in next months to know about that.
How about American players especially ?
I don't think the list will be as bad as you think but it will be surely weaker than previous years ... where Washington already was one of the weakest ATP500 tournaments).
Then yes : it will be cheap points.
Not only that but also I guess that players who will choose not to play the Olympics might be better prepared for Toronto on next week,
and that with all of the best players playing the Olympics, maybe playing also doubles, mixed doubles, with the different surface and jetlag, Toronto might get a "cheap tournament" as well, not a "top-4" property.
I guess choosing not to go to the Olympics might be a very good choice ranking-wise.
I wonder how ATP made the calendar for 2012 giving Washington 500 Series Tournament in a same week with London Olympics, it it little bit weird.
I think they had no choice : Los Angeles, Atlanta and Newport "own their week in the calendar", they paid for that, and they had no interest in changing themselves.