This may sound like a daft question and I apologise if it is, but how would one company (disney) sell a parade to itself?
Disney is very much into cost centers and separate budgets for lots and lots of departments, and bills itself for almost everything.
In this case, it's more than that. DLP is actually a separate company owned partially by Disney and partially by others. From Disney's annual report
The Company has a 51% effective ownership interest in the Disneyland Resort Paris, which is a 4,800-acre
development located in Marne-la-Vallée, approximately 20 miles east of Paris, France being developed pursuant to a
1987 master agreement with the French governmental authorities. Euro Disney S.C.A., a publicly-traded French entity
in which the Company holds a 40% interest, and its subsidiaries operate the Disneyland Resort Paris
So a transfer of assets between Disney and DLP corporate entities has be done via some kind of sale, or the non-Disney owners of DLP would be treated unfairly.