The article is actually IMHO overly conservative. This kind of migration is not a theoretical risk, but well established. BPA is a small molecule, not covalently bound to the plastic. It absolutely goes into the skin. Heat, water, and acidity (sweat is slightly acidic) all accelerate the absorption.

Plus absorption through the skin is worse than oral. Because when you eat it your liver breaks a lot of it down. When it goes in the skin it bypasses all that.

But are the quantities significant?