They DO have decent localization though.
Starting from 2017 they started making traditional and simplified Chinese subtitled games. Zelda has subs, and so did USUM.
Yes it's mostly for the taiwanese/Hong Kong market but still
Switch's selection of simplified Chinese translated titles is few and far in between right now ... (not many in the mainland know of traditional Chinese anymore)
The fact that the Switch has yet to release in mainland China is a massive red flag. For comparison, the PS4 launched in mainland China OVER 4 YEARS AGO. It's not just going to be localization issues though since the Switch won't release until maybe next year ...
In all honestly, Switch's launch in China won't mean much in the grand scheme of things since Nintendo has dropped the ball in it's preparations for that market. The portable design in favour of the Switch won't matter much to the Chinese by the time they have a 5G network to be able to stream games from their own PCs. FWIW, to the Chinese the Switch alone in it's current or future state won't be a very compelling offer to many. Had the Switch launched last year instead things may have played out somewhat differently but now it's just too late to make any impact ...