Contrary to popular belief, there is such a thing as over doing it. I really don't believe that adding another park is going to increase sales, but, even if it does it will not increase profit. With Universal expanding, Disney will really be competing for people to fill the 4 parks. Unless it is something never heard of and costing in the trillion dollar area they will no longer be able to draw people away from Uni just by building another park. While Disney spent the last decade napping, they were winning over some of the guests that one time only went to Disney plus attracting a newer generation that wasn't necessarily brought up with Disney like many of us were.