Re: What's under the paint
It's not just how the body wood absorbs finish at the factory, it's also (like JemRBK eluded to) done so the guitar ages better. So the different pieces of wood don't telegraph through over time, as they each expand and contract differently. There's no need for it on the sides or in the contours because it's really just to help the flat parts stay flat. You won't really notice anything like that on the sides. As for absorbtion, if it saves them 40% the sealer soaking into the top and back, that adds up quickly. But then there's the expense of the veneer and lamination process, so I really don't understand the practice at all, but I know it exists.
Now I have no idea what guitars would have it or not. I'd say it's more scarce. And it can't just follow the "multiple piece body" theory because that would make those guitars slightly thicker. Which isn't a big deal, there's 1/8" paint on there anyway, but I'd think that extra veneer would mess with the CNC program dimensions. So I'd expect it to be something done on a "per model" basis, rather than mixed in. Or at least a "per production run" basis.
All you can do is strip away and see what treasures are hidden underneath that stuff.