Interesting.
My understanding is that Teflon, unlike some plastics (eg Nylon and Delrin) does NOT absorb any water. However, we have heard that the 787 has a very thin layer of Teflon to save weight, so I wonder if there is a possibility of flaws in this coating or wear/abrasion damage.
Powder Coated steel can rust anywhere the steel is exposed by flaws or chips in the powder coat, or if the steel is not thoroughly de-rusted before coating. The rust spreads along beneath the powder coat until it starts flaking off, to a faster and greater extent than painted or stove enameled steel.
I am wondering whether aluminium wiring, exposed anywhere to a hot and humid environment, could behave in a similar way to powder coated steel, and oxidise faster than usual and cause increasing damage to the thin Teflon coating.