I was there a week and a half ago. On March 11, the hours were posted as 10am-10pm. The next day, Sunday March 12 (first day of daylight savings time) the hours were changed to 10am-11pm.
I wish that the hot tubs at Animal Kingdom Lodge could stay open later than the pool, since they are fenced separately and don't have lifeguards anyway. Other deluxe resorts leave the leisure pool(s) accessible after the feature pool closes. Since there are no leisure pools at Animal Kingdom Lodge, they close everything at the same time. I sent a message suggesting this when I was there and got a call from a manager saying they would pass it up higher.