Sure they can and Disney has been doing it for years. The Crossroads was originally Disney property. They de-annexed it from Reedy Creek Improvement District (RCID) and sold it off. The area around Little Lake Bryan (think the Vineland Premium Outlet mall area) was Disney owned. I think they still own a small portion that encompasses the Disney Cast Member "retreat" that they built years and year ago.I am curious. The land if Florida. Could a corporation buying Disney ever split that land up. It has to be worth more than the entire company in real assets.
The town of Celebration was built on land owned by Disney. They de-annexed the land from RCID and built Celebration.
There are other examples.
The reason I mentioned RCID...Think of RCID as the 68th county in Florida. This was done so they can set their own building codes among other things. They have a board of "supervisors" that get elected by property owners. Disney deeds a token amount of land to a few people tied to the company. The people that now "own" the land vote as Disney see fits. Thus the need to de-annex property so they can still control the "county" that remains.
So if someone buys Disney and decides to sell off the Theme Park division. The buying entity can do whatever they want with the land.