The Chinese market is potentially hugely lucrative, but the country's laws and logistical challenges make it a tough market to crack, especially for console manufacturers. There have been some efforts by Sony and Microsoft with their hardware, but little suggestion over the past couple of years that either company has enjoyed a major breakthrough. The high price of the systems (when Chinese consumers are familiar with cheaper gaming options) and difficulty getting some game content approved are among the challenging factors at play.
Nintendo stated it was exploring options a few years ago but, in summary, has made no discernible moves in hardware for China in the past few years. Earlier this year, though, New Super Mario Bros. (the DS original) was approved for sale in the country, and that was speculated to be part of a content sharing agreement between NVIDIA and Nintendo. The two companies now have a strong relationship through the supply of Tegra technology on the Switch, and it seems NVIDIA is bringing its Shield hardware into China. The suggestion is that Nintendo may allow NVIDIA to publish select games on the Shield, but this would only be in China.
As a follow-up, now The Legend of Zelda: Twilight Princess has been approved for the Chinese market, as shown by Niko Partners analyst Daniel Ahmad.
It's an interesting potential route into the Chinese market for Nintendo, and a chance to partner with NVIDIA to get key (albeit old) releases onto hardware. In other major territories Nintendo tightly controls content to promote and support its own hardware, of course, so these potential releases through Shield would be specific to the challenging market in China.
It'll be interesting to see whether these listings do emerge as full releases in China - as an enormous economy with a growing games industry, both Nintendo and NVIDIA may be looking to earn some welcome extra revenues.