My thanks to Zev Eleff who found a document entitled Tentative Faculty of the Department of Jewish Studies, Bernard Revel Papers, Box 36, Folder 1 20, Yeshiva University Archive where Chief Rabbi R. A. Kook of Palestine is listed as a visiting lecturer for the academic year 1928 1929. It seems that more evidence might still be forthcoming about Dr. Revel's vision of bringing R. Kook to RIETS Yeshiva College.

I found two documents indicating that R. Kook received an honorary doctorate from the University of Bern. Indeed, Rav Kook had resided in Switzerland from October 1914 until January 1916, and an honorary PhD might have been initiated by the students who set up Tachkemoni, Vereins jüdischer Gesetzestreuer Studenten in Bern (Society of Jewish law-abiding students in Bern) as the organization was spearheaded by two of  Rav Kook leading disciples, B.M. Lewin and M. Seidel.

If anyone has any leads on this information, it would be most appreciated.