Janet Rosen

I'm not sure exactly what you are asking...?...students may start training at dojos run by say a nidan then move to someplace they can train with a shihan in same or different organization and meanwhile the original instructor due to unaffiliating or injury or whatever may not get higher rank anymore or for a while...meanwhile the student keeps training so sure it's possible.

There is a difference, IMO, between "advancing in the art" and getting higher rank :-)