We must also note that Hitler didn't think highly of Lutherans anyway, and he, himself, was not a Lutheran.
I imagine he was quoted now and then. And studied in German schools
Whatever Hitler's personal views, he knew how to present a winning platform to the German people. Anti-semitism was part of it, and Luther is the patron saint of anti-semites. (Not that it was unheard of in Catholic Bavaria and Austria; think of Adolf H. as ecumenical). Luther may have used "Jew" as a code word for "Catholic", but I wonder how many people quoting him knew that. (I certainly never heard it before) And sometimes "Jew" meant "Jew".