I asked AI Overview:

Is a person of mixed English and Bangladeshi heritage known as Banglo-Saxon?

No, “Banglo-Saxon” is not an official, standardized, or widely recognized term for a person of mixed English and Bangladeshi heritage.
While it functions as a clever, informal pun or portmanteau—combining Bangla (or Bangladeshi) with Anglo-Saxon (historically referring to the English)—it is not an established ethnic classification.