I doubt if the author of the article has seen “Patterns of Evidence: Exodus,” the movie documentary that came out on this subject last year. Quite a bit of evidence for Semitic activity in Egypt has been uncovered at Tell ed-Daba (Avaris), for anyone willing to look.
See the book,
Israel in Egypt: The Evidence for the Authenticity of the Exodus Tradition,
by James K. Hoffmeier
Lots of evidence, it seems.