While I don't really believe that "yield protection" exists generally, you may be its rare victim. JM knows you will get into better schools and go and doesn't want to waste a spot on you or doesn't want to spend the scholarship money to get you there. I had a higher GPA (high 2s) and a lower LSAT (low 170s) and I got rejected at CUNY. These things happen.
I have a 177 LSAT and a 2.08 undergrad GPA. I was notified by email that I was accepted at Northwestern, but I was rejected a couple weeks ago by John Marshall. How does that even happen, since John Marshall is a TTTT while Northwestern is T14?