The link explains the reasons for moving to a new Foundry but it doesn't answer the OP question about the Ryzen CPUs being manufactured in Malaysia rather then in China.
I suspect the OP may believe the Chinese may make inferior CPUs than if was made in Malaysia. Anyway that is the impression I got from his question. That is why I was asking for the reason behind the question.
From Wikipedia concerning all of TSMC Plants. List of semiconductor fabrication plants - Wikipedia
These are all the GlobalFoundries Plants locations:
Both companies have a plant in China. But none in Malaysia.