I worked on it nearly a decade ago but getting silicon made for u2f was expensive and the appetite by consumers was insignificant.
I met Google team re u2fs in I think 2017... There was an appetite there but it was unclear if they would acquire ubikey at the time and legal problems.
Afaik multos has an applet now so it's likely any ring using multos (instead of global platform) should be able to provision the applet.