As far as I could tell from everything I've read from multiple sources, every Pixel since Pixel 4 _has_ the chip, it's just not enabled and you can enable it with rooting.

https://xdaforums.com/t/global-pixel-device-unlock-felica-su...

The chip is not missing, the configuration is.

I assume it's a licensing issue, where Google is too cheap to pay JR for the phones sold outside of Japan, so only setup the JP models and only pay the license for those.