I would love to meet the Rebbe or Morah with the courage to teach it that way. Of all the moros and rebbeim my kids have had, I may be able to count on one ... finger.
However, the first comment by Anonymous offers a plausible לימוד זכות. Perhaps Bisyah is an Egyptian form of the name and once she converted, it became Basyah which is more of a Hebrew form. The problem is, was this really her given name? It's hard to imagine פרעה would name his daughter such. It's more likely this was a name given to her only after she converted.