Disconnect client on invalid disconnect

Hello,

The current draft normative statement MQTT-3.14.1-1 states

"The Server MUST validate that reserved bits are set to zero in
DISCONNECT Control Packet, and disconnect the Client if they are not
zero."

My feeling is that this implies a Will should be sent out because it
is not a valid DISCONNECT flow, but it isn't clear. Can this be made
explicit please?

Thanks,

Roger