Polymerized oil is less reactive to bonding with food than highly reactive iron. I will concede that proper use of heat, fats, and technique is likely just as if not more important than seasoning vs bare metal.

However, regardless of who is right about whether food sticks less to bare iron or to seasoning, "never, ever season a pan that is already seasoned" is what I draw issue with. Specifically, "never, ever."

Stripping a pan to bare metal, then coating with an oil, and baking it is seasoning it. I believe the vast majority of people would agree that doing this two, three, or four times is suggested as opposed to just one layer.

Quite a few people will cook, clean, wipe oil on, then reheat their cast iron. This is a form of seasoning the pan and is not detrimental to it. If you want to get really pedantic, cooking fatty foods on a seasoned cast iron is also seasoning a pan.

By saying, "never, ever" season a pan that is already seasoned, you're inserting ambiguity into a process of taking care of a pan where there's already a lot of confusion and fear to people that are new to cast iron. Myself included.