From my experience, I don't think this is true (at least not in the way that matters). I finished my PhD in CS as few years ago from a good school and I am now a researcher in industry. In my time in grad school and industry, I have only seen one of the many Chinese nationals I met during my studies return to China. The Chinese researchers and interns I work with have no desire to return to China. The interns express concerns about job opportunities and quality of life if they were to return to China after finishing graduate school. I have never met any non-Chinese researchers who expressed interest in working in China either in industry or academia.

Obviously this is anecdotal so take from that what you will. The computer graphics and machine learning communities in academia and industry are small (even with the ML/AI explosion), if this was happening in any significant amount it would be difficult to miss it.

As for research output, I think there are definitely more top-tier papers from Chinese universities than in the past. It still seems like there are more Chinese surnames from Europe and NORAM universities than from Chinese ones. The big names in the field are still in European and NORAM universities.

I wonder how these are articles you linked are counting numbers. It's hard to understand how something like this could be happening completely under the radar.