Traditional IPv6 autoconfiguration assigns addresses based on a prefix and an InterfaceIdentifier generated from an EUI-64 that is specific to each device (or interface). NeighborDiscovery is the protocol that is used for defending addresses determined this way, as well as for obtaining the parameters for the prefix(es).
To achieve RoutingScalability, AddressAssignment needs to consider the routing hierarchy.
There appears to be strong consensus that (IP layer) AddressAssignment should in no way be coupled to application layer semantics (as in "Thermostat 3"). (In other words, the classical ID/locator pair is complemented into the triple Semantic ID, Network ID, locator.) The InstallationProcess is probably the right time to fix the Semantic ID.