Re: "but Android doesn't support that"
Android does support RDNSS, but you know what doesn't support it? Windows!
So really, if each manufacturer is left to pick and choose what standards they want to implement (Why the F*CK doesn't Windows support open file systems like ZFS, EXT, etc!?!), then why does Android get the blame just because Microsoft chose to implement DHCPv6 and not RDNSS? If Google were upgrading, they'd probably be complaining how difficult it was to get windows PCs on their IPv6 network without DHCPv6.
Everyone is to blame here, just easy to hate on Android when you're Microsoft.