For many people (*not* all), it is not a myth. Please see my recent post from a few days ago. We need to hear from more people who have similar symptoms in order to help determine the cause amd solutions.
There is somehow related but my dermatologist claims that increased level of sebum production is natural companion of androgenetic alopecia.
Let's assume that excesive sebum production is causing hair loss or shedding - then the question is what causes that abnormal level of sebum and how could we potentially limit it? Again nothing but questions...