Doesnt really matter, many of the sources use the same source, use whatever you want. I did not find the 808 sq m for the 747, nor the 680 sq m, that you found on wiki something. Wiki data is not really vetted, I can go up there and edit an entry with whatever I want, it relies on someone to review it, whenever they get around to it or there is a comment about the validity..
Luftansa does extensive studies on their ac, one of which provided the wing root data down the wing, which is what I use.
Same for the 787-9 and the Max data, scientific papers as submitted for the wake turbulence validations.
Again, some Airbus data includes the center wing area, so one has to be able to sort that out of the mix, so as to make a relative comparison with the other data.