Not at all the same thing.

Ego-death can be brought on by yourself, with extreme introspection and seeing yourself from inside your body. The end is realizing your body is not you. This sometimes can be done by situations, but usually done in some branches of psychology, or by an occult practice.

Narcissistic collapse is when the facade of control by a narcissist is collapsed down around them forcefully, and they then have to deal with the fact they are not the center of the universe. This loss of control causes them to spiral inward, and then lash outwardly very violently. They , in almost all cases, lack the capability of addressing the causes of narcissism or the damage they cause others.