will message persistence

[Ozan t]

Hi,

This quote is from spec : 

"The Server SHOULD publish Will Messages promptly. In the case of a Server shutdown or failure the server MAY defer publication of Will Messages until a subsequent restart. If this happens there might be a delay between the time the server experienced failure and a Will Message being published."

It looks like spec assumes last will messages will be persisted as it refers to being sent after restart.

So, my understanding is last will messages must be persisted even client is connected with "clean session = true" ?

Is that correct?

Thanks,

Ozan.