Tokyo DisneySea is clearly Magic Kingdom 2.0 for that resort and everyone seems to praise it to high heavens. There's nothing wrong with the pattern of a MK type park as long as similar ones are given some unique qualities, high quality attractions and good placemaking.
The problem with Epcot going forward has nothing to do with being like Magic Kingdom (it's really nothing like it, so that's a silly complaint - having IPs doesn't make it like a castle park) but in lacking cohesive theming. It would be possible to add significant amount of IPs and still fit in well with the premise of the park.