Unfortunately this notification is a defect; and yes, you can see it any way you like, be it by design for legal reasons or not. So instead of arguing the point, let's start with the problem, rooting is not an option for warnaties (ha ha legal people can sniff that option); oops here I go.
I fail to see how anyone can make the assumption I will be around to unplug the thing before the battery catches fire or when it fails to deep-cycle the lithion whatsits ions because I'm not around to unplug it. All the solutions I have googled either do not work on my device, or involve hacking, which is not something a customer should be forced to do within 4 hours of receiving the device just in order to get a night's sleep. I mean even my car's filler cap does not have this bug, the petrol-pump just turns off. So I'm suspecting since nobody has quoted a Samsung bug tracking number that it's not been raised as a bug in the battery drivers. Having helped write drivers for a phone before, I know this is easy to get wrong, but this problem is getting a bit silly now.
Oh and P.S., the Galaxy S3 is awesome - I really really will root it if I have to, that's no threat. (yes, this same 'undocumented-feature' is present in a number of Samsung devices.)
[edit:] I just raised a ticket (I hope) - although the process was amongst the worst for raising tickets, so I may have to try a 5th time (yes, it really will take multiple attempts, that's a valid legal tactic.)