This is more of a thought experiment than a problem. I just want to know how ethical is it.
Suppose a student discovered a very cool theorem/result that would yield a very good academic paper in a very good journal. But the student know that the admission to the graduate program in his country is based only on a written test (which they are expected to ace), so publishing now will not be beneficial. So, is it ethical for him to save the paper for the rainy day in the future by publishing it under a pseudonym (hence the world will not miss out on the knowledge)?
A generalized version of this problem would if you are overproductive in a certain year, then is it ethical to anonymize the production above the bare minimum and use it in the future when you are going through a lean phase?