I graduated Jan 2007, we had:

GySgt
SSgt
GySgt
SSgt
Sgt

In that order. Both Gunnys pinned on during our cycle. We weren't invited.

In Larry Smiths book "The Few And The Proud" they said it was pretty common during the Vietnam and WWII eras to take the platoon honor grad and make them a DI for the next cycle. This was due to the current NCOs in the fleet being tasked with the war. Pretty interesting.