I've updated my post to clarify since in hindsight it implied the OLC/Disney deal is in perpetuity. That said, for something on such a grand scale, both economic and logistic, as purchasing WDW and DLR (and possibly the other non-Japan parks as well), I can't imagine any company would be willing to take on the risk of "Disney" (a hypothetical future studio/IP holding company) not renewing their deal at the end of its term. That's why I keep bringing up perpetuity in these discussions. Maybe the park company could justify it with a long term agreement, like 75-100 years, but even then, if they don't renew the IP license, they'd have to shutter all their parks, which are (obviously) physical places and worth billions.
Compare this to a streamer like Netflix losing the streaming rights to something like The Office. Yes, it's a big financial investment, but removing the title from the platform is a rather simple process and Netflix continues to operate after it's done. Presumably, the theme park company would only have Disney's former theme parks as their assets, so they'd lose all their revenue and have all these physical properties lying around that they can't make money on until they remove all of "Disney's" IP, a herculean task involving even more untold sums.
The terms of a deal like what we're describing would be insane, both economic and non-economic, to be able to accommodate the park company's need to ensure long-term use of the IP, and thus, continued operation of the parks themselves.