An aside: whether to allow the randomized addresses or not is a choice available today with no protocol changes whatsoever. A network admin can turn off the "

An aside: whether to allow the randomized addresses or not is a choice available today with no protocol changes whatsoever. A network admin can turn off the "A" bit on the prefix in the router advertisements and turn on "M", and the compliant hosts will use DHCPv6 to get the address, which one will allocate statically per-user. This is exactly the same as "no privacy addresses".