Yeah, they sign up with Beijing Zhong Ke San Huan High-Tech Co...

Yeah, they sign up with Beijing Zhong Ke San Huan High-Tech Co Ltd a couple of years ago to provide them the sintered Nd-Fe-B magnets for Tesla 3 and Semi. They have the entire range of magnets produced on their web site http://www.san-huan.com.cn/ from fridge magnets to EV magnets.
The main reason Tesla went with 3 ph instead of PM was the supply issues 6-7 years ago which is no longer an issue now the Chinese are supplying the magnets and likely that in the near future to start building at least one Tesla model as well. There is method in the Chinese "madness" of accumulating and building up inventory of Dy at current prices.

AFAIK all EV motors that use Nd magnets are using Dy in various amounts depending on performance and duty required. Apparently Honda has apparently found a way to remove terbium and dysprosium but to do that they have to replace it with lots more neodymium so not sure that replacing 40g of Dy with 400g of Nd would make much sense even putting aside any loss of performance and reduction of max. operating temperature.
Same with Toyota's claims of reinventing the wheel
" Toyota has come up with a way to cut out the expensive metals from the magnets and also reduce the amount of neodymium in favor of lanthanum and cerium, which each cost around $5-$7 per kilogram.

Kato declined to give specific details on cost reductions, but said that Toyota could replace up to half of the neodymium used in magnets for motors which operate conventional vehicle functions like power windows with lanthanum and cerium, and around 20 percent for electric motor magnets."

You'll notice they could cut up the Nd used by 50% but only in power window motors and probably only on the cheaper end of EV market where only the front windows are powered. Same for EV motors where they would put in a 20% smaller motor , like they do with Prius 1.5 v Corolla's 1.8 motor claiming a 20% fuel economy on the hybrid.

Performance of Nd magnets stars to degrade once temperature goes above 120C and rotors in EV motors run at around 150C so adding 40g-60g of Dy is only a tiny fraction of the cost of a motor even if Dy prices hit $700/kg again. Despite the trolls claims that Dy is obsolete the reality is that without it the Nd magnet in EV motors is as useful as a chocolate teapot.