Even if they pulled all manufacturing from China, they could still potentially be kneecapped if China blacklisted them from purchasing things like gallium.
I don't think they had a choice not to operate in China in any practical sense.
They could have not been a large scale electronics manufacturer, but then they don't operate in China by making an entirely different kind of choice to be an entirely different kind of company. I don't think any electronics manufacturer (or meta-manufacturer/designer/whatever/globalization is weird) within an order of magnitude of Apple's scale can practically operate without benefit of China's manufacturing base.
It feels like you have to bend the intuitive notion of "deciding" to operate in China even means for this to make sense and you just want to pin something on Apple here because they're a giant corporation, and all giant corporations are morally gray at best. The global economy has "decided" that China has the manufacturing base for this kind of business.
This doesn't seem productive in the way that appeals to personal responsibility fall flat in dealing with societal issues, like, we shouldn't have public drug treatment programs because people shouldn't do drugs. People do drugs, and there are costs to not having public treatment programs, so if you want to pretend it's just a matter of personal responsibility, you are indeed pretending, because it is also a societal problem not negated by framing it as personal responsibility.
Here, we assign "personal responsibility" to Apple for operating in China, when we have the "societal issue" of large scale electronics manufacturing centralizing there so that they have the industrial base for it. The world, on the whole, has allowed China to link into the world economy in this manner regardless of their humans rights record and other issues.
So, while there's nothing to love about Apple here, I feel like it's really missing the forest for the trees to frame this as an "Apple" issue in any sense whatsoever, but should be framed as a China-human-rights, globalization, and world economy issue, and we don't do ourselves any favors with appeals to "corporate personal responsibility"
Apple made a choice folks... and it was to sell out to an oppressive regime. There is no other way to see this.