I think parent is saying that Asus (and everyone else) will try to enforce illegal terms WRT to unlocking voiding your warranty. From what I understand, this is very much the same with car companies trying to tell you that you void your warranty by not getting all service done at their shops (or failing to get timely service on systems unrelated to the covered part failure.)
I see. Well, whether unlocking the bootloader voided the warranty or not didn't matter in my case, since the phone seems very resilient so far. It has fallen in the toilet and had yoghurt spilled directly into the USB port and it's still trucking along.