Wouldn't that pertain to a different era? I agree with him insofar as it's about the period after the heydays of Ptolemaic Egypt (and I even have some doubts about them doing it), since I don't really see anyone except a very powerful ATL Byzantine Empire pulling it off after that point. But if Alexander had actually lived long enough to conquer Arabia, I'd say it's very much a different ballgame.
If the Ptolemaics can conquer and hold the Hijaz and Yemen long enough perhaps. They could definitely influence the Arabs, however, it may turn out worse for them. Look to the example of Hellenism and the Jewish people for how these sorts of things can go south very fast.