I know this thread is somewhat old, but I thought I'd share my experience for others that will search for this in the future. I cancelled a room only reservation on Saturday, February 24, and the refund appeared on my online credit card account on Friday, March 2 as a refund on Tuesday, February 27. So I assume the refund was issued by WDW on 2/27 and applied by my CC bank on 3/2.
By the way, I found this thread very helpful, and I appreciate all the previous posts' answers.
Have a great day!