Definitely has not been noticeable to me. Have done night shots, with and without the display light on, and not seen any difference in exposures. Considering this is the first body that I have had all my zoom lenses not need any AFMA whatsoever, even though it ironically has superior adjustment capabilities, there is little chance of it being sent back for fixing something that isn't a problem for fear of mucking something else up. As I doubt resale is likely to happen for many years, I don't think I'll be losing any sleep over this.

Of course, if it turns out to be replacing a defective weather seal that is something worth sending it back for.

you don't think this could be a cover to turn off the self-destruct do you???