You think they would sell off something that is even the second biggest source of revenue. Sorry wont happen. Something major financially would have to happen where Disney couldn't afford it. And at that point Disney would first cut things before they give up WDW. So wont happen.
It may be their second biggest, but again it only accounts for thirty percent of overall revenue. Again I'm just looking at this from purely a financial perspective and not an emotional one. Disney can afford to keep or sell the park at this point, but it's what makes the best financial sense that makes the decision. If a sale made sense they would probably do it.