If The Walt Disney Company was sold, very little would change. DVC members would still have their full ownership rights. There may be some changes in relation to non-guaranteed perks and benefits. (Some would argue that we'd all be better off if TWDC--or at least the theme parks division--had new ownership.)
If Disney Vacation Club was sold to another timeshare developer or manager, it would likely have greater impact. Folding DVC into something like Hilton or Wyndham would make owners part of that system. There would still be some home resort priority period, but could be greater competition for booking non-home destinations.
In the greater timeshare world, DVC is very much a niche product. DVC resorts aren't the "Crown Jewels" that some members may envision. But it's also a niche which has proven very valuable to Disney. If Disney were to entertain selling DVC, they would certainly want a premium price. But I'm not really sure why another developer would pay that premium. Owners of many other timeshares can already trade into DVC via Interval International.
Meanwhile Disney would be surrendering a massive amount of control over the DVC product and the resorts themselves if they sold. They would be giving a third party some degree of authority and operational control over a dozen properties which are enmeshed with Disney cash hotels. Again, it would have to be a very lucrative deal for Disney to even consider.
