Around here, institutions are quire rigorous with that, so stores have to play by the book. Only very small shops can sell pirate software without getting caught
About the distros, Each brand seem to put a different one, and they're all weird. Mine came with some sort of modded debian with alternate repos, but was very impractical for use, and ended up installing fedora over it.
Exactly, but if we think about it, just putting some random well-established distro would be faster and cheaper than creating their weird modded versions or making contracts with weird firms. Maybe they want to avoid any unexpected legal issues?