Well, there are a number of examples of all the things "China will not/never do/become", that China actually did and became.

"Politically, China has mostly been left alone in its own way, as reflected by how the West has engaged with China in the past 30 years." I have read this sentence several times and still don't get what it could possibly refer to.

Quite often there are unfounded, unprovable, blanket assertions, that are left standing, unchallenged, and therefore become fact.

Can you please elaborate, what are the specifics of the case you are making, while staying clear of common place generalisations?