The term “Anglo-Saxon” is anachronistic in the extreme. Anglo-Saxons spoke Old English and lived in England and southeastern Scotland in the Early Middle Ages. Their origin traces from Germany in the 5th Century.
Things have changed since King Alfred. WASP is useful as a term describing word origins which come from the Old English.
Yep. But they chose to use it.
Even the British are mostly not Anglo-Saxon and have not been for a while. With the arrival of the Norman-French and prior to that of the Danes the Anglo-Saxon genes took a beating.