I think he learned a lot about socialism and government control from his failed vision of EPCOT, when he had to make it into a theme park instead of utopia.
I think that the idea to turn EPCOT into a theme park rather than a city happened after his death. I may be wrong about that, but I recall reading something along those lines a few years ago.
But, the Epcot Center opened long after Walt Disney died. Did the Disney Company change Walt’s ideas for the Epcot Center?