As the offspring of an English teacher....I thought that was common knowledge. Of course, there was a huge impact of French on Old English after the Norman invasion.
Yes indeed, what a ridiculous article/discovery. Fifty-five years ago at the Univ. of Iowa (home of the well known creative writing school), English PhDs were required to study Old Norse and Middle English. Other important language are Old French, Anglo Saxon, Latin, Greek, and French. Some people will say anything to make their name, even things that are well known for ages.