Apple Watch Ultra Cellular Compatibility between A2622 & A2684

Hi,

Can I contract cellular using Apple Watch Ultra Model A2622 (US version) in Japan where A2684 will be sold.

The reason of this question is now I'm living in US but I will move to Japan in a few months. According to the last event, international roaming have come to Apple Watch. However, as long as I compared messages between previous watches which I bought in Japan and US, I couldn't know if I can contract cellular plan in Japan with new Apple Watch which is sold in US.

Thanks