With a fixed sensor size, you will have more light per "pixel" if you have fewer of them.
But the reason the moon looks white is that they overexpose. The user is in control at least when camera api2 is in use.
Taking photos of the moon is not really the main use for a phone camera, so it shouldn't be the main benchmark either.
But I was thinking the manufacture should provide a camera app which supports manual ISO&ShutterSpeed&Expose adjustment in pro mode, since it has 'reached' 48MP...
(Lumia 909 & iPhone's built-in camera app didn't support manual adjustment, but after installing third-party apps like LumiaCamera(dev. by MS) and XN Camera(not by Apple), these funcs worked perfectly...)
I was confused that since these phones support these functions and even have a tag 'focused on photograph' , why the manufactures didn't provide those apps and users have to download third-party apps to 'unlock' them...