I doubt that there was ever a “legal” definition of AWD vs 4WD.

But in modern times, technology has most definitely blurred the distinction. Higher-end Jeeps also have a “full-time 4WD” that sounds an awful lot like an AWD system that can also do 4WD stuff.

So, eh, it’s probably not a good idea to argue too much about broad categories anymore. Individual systems must be compared