So I got an offer form an alumni to have a phone conversation with her. Unfortunately, I was unable to go through with it (she also did give me very short notice in my defense). Will this affect my decision?
Unless you were at a funeral or receiving a prestigious award at the same time, you should have changed your schedule. If you are admitted, it had no impact. If not, you’ll never know if that was the reason.
Cornell only “consider” interviews, I believe that they will not base their decisions on it.
It has essentially no impact, it’s not a real interview, more like chill. It NEVER negatively impacts your application, if you were gonna get in, you will regardless.