No, I've received two 8th day releases and then got the paperwork in the mail about 2-3 months later. The ND dates stamped on them for each were just a few days prior to me receiving the papers.
I assume these were for a private sale via an MSP barracks? I figured the firearms would not be registered until the MSP "NDs" the applications. I find it unlikely the MSP will inform all people who received 8th day firearms of their "NDs." I could be wrong.