I don’t think the hypothesis is outside of genetics either, even if it’s not based on genetic facts. OP thinks that the white earlobes are caused by an extra layer of skin.The Hypothesis has no genetic basis to stand on.
White Earlobes and White face trait in Chickens are a Polygenic Trait with some of those genes beign Sex Linked but most are Autosomal.
The Red Jungle Fowl has White Earlobes, The introgresion of Grey Jungle Fowl not only Brought Yellow Skin/Shanks but also red earlobes, interestingly enough the Green Junglefowl being a Basal Junglefowl has the most colorful of faces and when outcrossed to White Face Spanish The F1 show complete White Face.
I've been thinking of a creating a Blue Faced breed with White Face Spanish and Mosaics.