One of the problems with Pirate's Lair going into Tom Sawyer Island at MK is that in DL, the island is directly across from PoTC. At MK, this is not the case, and as a result, it would be very poor theming to have a pirate island that is nowhere near the pirate attraction (not that theming has been the most important thing for WDW executives lately...um, hello, Laugh Floor?).