When I was like 12, it was soon after EPCOT opened. I snuck into an off-limits room at Communicore. It had renders of future attractions. There was also a gigantic plaster board with the US Geological Survey of the WDW property. It showed the property boundaries. It also showed a solid line for the monorail system and a dotted line, defined in the key as "future monorail". The dotted line ran east of SSE and wrapped around the WDW Village Lagoon. When I first looked at it, I thought that was the monorail that loops around the Seven Seas Lagoon, but when I took a closer look, I saw that loop was near the top of the survey.
Since then, everyone I told this to said I didn't really see what I saw and it was the product of child's imagination. It wasn't until recent years that I begin to find pieces of things that showed that maybe I did see what I saw. I am confident now that my memory of it is a correct memory.