Nobody is forcing them to build in China, disney just wants to make more money for themselves, so China can do whatever they want since it’s their land. If Disney agreed to this terms - it only means that it’s still profitable for Disney.
The issue is: China is barely an accessible market for even the most powerful and largest of international corporations. Their rules for domestic entities are dramatically different than the rules for foreign entities, which is an intentional effort to restrict foreign competition and access to their economy. China wants to have its cake and eat it too.
Developed economies will increasingly shut down China's access in the same manner as China does, ending China's free ride. That process is already well underway with the US and Western Europe, as both have begun blocking China's ability to acquire local companies and technology. China will find it increasingly difficult to sell higher value products into the US and Western Europe (by far the two wealthiest economic regions on earth), restricting potential economic expansion for China.
Then again, maybe they're ok sacrificing long-term global growth to increase their domestic situation to something comparable to Europe or the US, at which point it won't hurt as much...
Disney can't even own their own park in China, they have to be a minority owner. So they build a nice, very expensive park, Disney Shanghai, and get 43% of it. That's the world's largest, most powerful media company, forced to beg on its knees just to get access to build in China. That tells you everything you need to know about how accessible China really is.
How's this for an example of how Chinese law works for outsiders? Jack Ma stealing tens of billions of dollars from Softbank and Yahoo, by taking Alipay away from Alibaba shareholders without proper compensation and without shareholder voting. He gave it to himself, discharging it out Alibaba and into his own hands, with complete disregard for what the ownership percentages were of Alibaba. It's one of the greatest thefts in world history, and these other large corporations were powerless to do anything about it. Ant Financial / Alipay of course is a critical piece of Chinese technological infrastructure, and is likely to go on to be worth a couple hundred billion dollars over time. For example this Wiki quote:
"In the fourth quarter of 2016, Alipay had a 54% share of China's $5.5 trillion mobile payment market"
That says it all about the extraordinarily vast scale of that theft. No chance China was ever going to allow Softbank and Yahoo to have such a big stake in that. So they looked the other way while Ma robbed the bank.
What outside technology company possibly trust being in business with Chinese tech companies on anything important or valuable to the Chinese economy after something like that? They'll just change or ignore the rules at will. I liken it to Jeff Bezos choosing to give himself most of AWS, discharge it out of Amazon.com's ownership structure, and not compensate the other Amazon shareholders for it. It'd be like Bill Gates granting himself Windows LLC, removing the product from Microsoft circa 1994 without shareholder compensation, and reaping tens of billions in additional gains that should have gone to Microsoft shareholders.