"He had his journey," the "Saved by the Bell" star told Andy Cohen before the reboot airs with the whole gang except Diamond.
Josie Totah, whose credits include the Disney Channel's "Jessie," will appear alongside Mario Lopez and Elizabeth Berkley in the NBC revival.
"This is what 30+ years of friendship looks like," actor Mark-Paul Gosselaar wrote of the reunion dinner.
Elizabeth Berkley will dance to "I'm So Excited" by The Pointer Sisters. According to E! Online, the "Saved By The Bell" veteran will dance the jive to the song she infamously sang and danced to in an episode of the TV series.