I teach all levels of piano and have no degree, just some piano performance and music education in college. Currently one of my students is working on Clair De Lune (Debussy), 5 flats, 9/8 time, while another student is still trying to find middle C. With 30 plus students a week I don't have time to go over all the advanced pieces some are playing. At the advanced level your instructor is there to offer you accountability, not demonstrate the songs you are learning. I ask advanced students NOT to listen to a performance of a song until they are almost ready to perform it themselves. I know they are reading the piece instead of playing by ear, and the artistry in the music is coming from them, not just being mimicked. If you have found a teacher you are comfortable with, who keeps you moving forward, don't change. My former piano instructor told me many years ago the best compliment a student can give is outgrowing their teacher! When we have taught you everything we can, we know it's time to send you on. A good teacher will recognize this. Have you asked yours?