you are losing your mind over a fan shroud.
open source does not automatically extend into any and everything you do that touched something open source.
if he would like to make a profit off his work he will associate a cost to it and then place it on a marketplace from there the free market will take over and dictate if they would or would not like to buy it.
take his work and copy it you already have access to it.
it is amazing reading through the comments on this item. somehow this fan shroud is cursed to bring out the most toxic posting in people.