Back in Dubai's spending frenzy, when they practically would have paid anything to bring in a Disney park, Disney refused. Then the bottom dropped out.
Many of the Dubailand projects with the major players were canceled, others moved to other locations.
Interestingly, there was a deal for a Marvel Superheroes park. The park itself was canceled, but it appears the license was transferred to a Worlds of Adventure indoor park, so depending on the contract it might limit possibilities for a Disney park if the ever did decide to build one.