Yeah something similar was to be added, the crow's nest Pirate at the end of the drop but he was axed.
The finale for WDW was also to have been a treasure filed Island with this pepper's ghost effect too at one point.
Again, never heard that. Everything I've always heard has Pirates was cut down because the room for it in a proper location was not there. Never a plan to have a bigger and better Pirates (except probably in Blue-Sky fantasy, which I must say doesn't really count). Western River is sometimes still in the picture and still panned to be the big boat ride.
The most common POTC/Western River Expedition story I've heard is this:
Western River Expedition was to be WDW's POTC. At the time when WDW was being planned and built, everyone thought that POTC wouldn't be as big of a deal in Florida because of its proximity to the Caribbean, and pirate stories and legends were all ready a part of the culture. WRE would have been more of a cowboys and indians, taming of the west story. This was seen as more exotic than pirates for Florida. WRE was to be built after the park had recouped some losses and had some strong attendance.
When the MK opened, attendance was much stronger than expected and the audience was virtually the same as DL was seeing, and that audience wanted pirates, NOW. So the decision was quickly made to add POTC to not only please Guests, but to also add much needed capacity to the park (and a very empty area of the park). Because of the speed in which they needed the new attraction, it was watered down from DL's with plans to expand it later. However, after POTC was built, the company focused on larger projects for the Florida property (Space Mountain, BTMRR, EPCOT Center, etc).