Does this type of stemless, asymmetrical "U" have a name or classification? Is its origin linked to one particular country or era?
It's the Dax U.
IIRC, there were some VGC typositor faces that had this feature about 40 years ago, but never as popular as Dax in the digital era.
I call it spurless, but it's not an ideal term.
There is a bunch of typefaces featuring this detail nowadays. I call them “simple sans”.