Should packets be identified as multicast or unicast exclusively?

In the 1.2 specification, the ADVERTISE, SEARCHGW and GWINFO are identified as being "broadcasted" to potentially multiple receivers, whereas the other packets are not. The question here is whether we should continue to identify these packets (and PUBLISH QoS 1, or out of band) as broadcast (or multicast) only in normative text, or just call this out as implementation advice non-normatively.

Andy Banks is concerned that if it is the latter, then interoperability could be affected.

Ian Craggs thinks that which address to send packets on is an implementation decision, like the TCP/IP address and port of the MQTT broker in MQTT.