If they get bought out or merge with another company then 100% of nothing is nothing.
I don't know why you're so convinced that this is going to happen, but whatever.
Disney taking half of the profits from a property that they don't own is bad business for the company that does own said property, and Sony was absolutely justified in saying "no" to that demand.
The fact that Disney fanbois can't see past their own ears and recognize that is irrelevant.