Maybe its because DL has a higher percentage of locals, and therefore is recovering quicker than WDW?
I think it would have been a good time to leave DL's prices alone as well, but maybe the above reason is the justification. Also, with all of the rehabs going on at DL (and many more coming up), and all of the construction at both DL and DCA, I'm sure DL/DCA are spending more per capita than the WDW parks right now.
Not saying that's the optimal situation, because if they weren't waiting so long between rehabs at DL, and if they had done a better job with DCA, they wouldn't have this issue. Nonetheless, they are where they are, so maybe that's why prices went up.