Well partially true. With my recent upgrade experience ,4 computers, the newer the system the less to worry about but with older machines it will:
1.) Not get up-to date graphic drivers (I had to download both cataclyst and nvidia drivers for two machines)
2.) Used incorrect sound drivers (creative labs thankfully made new ones just a couple of weeks ago)
3.) Some older ethernet drivers might not work out of the box (realtek for me, intel worked as always)