To me having them not sell tickets to DCA, and closing the gates and not letting anyone reguardless of wether they have been in the park or not, means that they have shut down DCA due to capacity. If you all insist this did not happen, fine, I know the truth, and you can believe whatever you wish. I have seen them shut down both DCA and DL where they have stopped selling tickets to one or both parks. I have seen them turn people away at the parking lots and not let any more cars enter. I have seen them close the gates and not let anyone else into the park Period. Apparently all of this is in my imagination, even though it happens almost every year at DL between Xmas and New Years, and sometimes presidents week and Spring break too.
I admit I too was shocked the first time DCA closed it's gates, but it does happen, especially since it has a much smaller capacity than DL (I think it's somewhere around half if I remember correctly).