Look at it this way, if you were universal and have a rethemeing planned for lets say lost continent and you have a budget of around 500-800 million dollars. Well Disney comes in and says we will give you 200 million dollars if you retheme Super Hero Island instead. Would you be so quick to say no? Its almost free money. Its increasing your budget for the project dramatically, allowing you to build basically an additional attraction, or put that money away for future projects.
And as I said in my post, Its a land that takes quite a large amount of area, allowing you to do much more in it. Its an area that is flat, meaning that there is less ground work required which saves a large amount of money. There are no major water features that would need to be removed, lowering demolition costs, and if you desired a future expansion for it you can expand it into that deadspace between towards toon lagoon. Lost continent is landlocked between Potter and Suess, and its a very small land. Not to mention the amount of gridlock that would be caused if you put a major attraction next to the already crowded entrance to hogsmede. If anything that would be a good area to do another future potter expansion, although as time goes on and potter gets older and older with no new material coming out that may not be as economically viable as it is today. (Just like Avatar will be in 10 to 15 years, provided the sequels come out, as if it was even economically viable at this time)
200 million is nothing to dismiss in the theme park industry.
And remember when they refurbished spiderman they only put a new film in, new projectors, rebuilt some sets and thats it, they didn't change the story of the attraction so Disney had no reason to stop it, not that they would've if they could.
And Uni doesnt have as great of a maintenance department as everyone on here thinks they do. The reason people think they have such a great one is that everyone holds Disney to such a ridiculously high standard they think if it doesn't look exactly like it did when it opened its falling a part. Have you looked around the hulk queue? Its horrible, everything looks cheap, its dirty. If you look in the post show there are dead bugs everywhere, the lights on the ceiling are filled with them too. Universal and Ioa just look cheap and dirty compared to disney parks.
I agree that Marvel will never happen in WDW, TDO thinks they don't need it, nor do they want it, its just too cost prohibitive. It will only happen when Uni moves on and builds something else.