I fail to see the point. Last year, the DC final got over on Dec4th, almost an entire month before this season started. This year, there are 2 additional weeks. Plenty of time for whatever organization is needed. Also, the DC final would be over before the meetings next week which you mentioned. I agree that they can't include the results of all the late challengers, but DC is not late by any means.
It's almost as if the ATP is sending a message, "DC does not matter"
I made a mistake : it's not next but last week
Anyway I don't know really but what I generally mean is that it can also make sense for the ATP that "their" year ends in the WTF. Although it's not the end of the calendar year, which makes indeed some things difficult to understand, but it's like that.
But it's not a message "DC doesn't matter" either : the points from DC final last year do indeed count.
and even better : the points from this final will be the first points counting for the Race next year. That's how it was done last year for Nadal and Ferrer. Even more : in the Race, they counted the points from 2011 DC's final but not the points from late challengers in 2011 (which will be even more of a problem next year imo as the WTF being earlier, there are more late challengers, I wonder if they will include these late challengers in the Race for next year this time).
But it's true that the DC is an ITF event, not an ATP event.