I do not disagree at all. The Egyptian letters are so close to Hebrew letters that it's hard to tell the difference between the 2 ancient written languages. Joseph obviously spoke the language of Abraham, and he became the most prominent ruler 2nd only to the Pharaoh. It is logical that the language had a very close resemblance between them if not the same during Abraham's day.
In Genesis 12, Abraham relocates from Chaldea to Canaan. When a famine arises in Canaan, Abraham is told to move to Egypt. During his stay in Egypt, which could have been a few years, Abraham had extensive contact with the pharaoh and the upper echelon of Egypt. For example, verse 16 says that the pharaoh entreated Abraham. In other words, Abraham and his descendants had a decisive presence in and influence over ancient Egyptian civilization!
The nephew of Shem "Phut" Ham's son who settled in the land that became known as Egypt. I'm sure the language was the same with these brothers. Shem's son was "Lud" and he settled west northwest of "Phut." See Genesis 10:6 and verse 22. These are Noah's grandchildren. So what was the language spoken before Babel? That's rhetorical question is only for provoking thought for whoever sees and reads this.
May God Almighty bless you all.