Isnt that just... stealing? I mean, if that works, then im opening a fast food chain with a t&c you have to sign that legally allows me to take all your posessions...
I don't even know why I would use anything but the genuine Google parts. They are easily available on iFixit and aren't too pricey. Phones are expensive and I wouldn't want to risk damaging mine to save a couple of bucks.
I don't think Google should be doing this (or even reserve the right), but I don't think it's a good idea to use iffy parts when the genuine parts are so easily available.