Dian left in '93. Her final episode was aired June 26th 1993 so she still was on the show at this time just not in studio that day. They had Kathleen by that point, so there really wasn't any need to bring in a substitute.
@@evanwilliams6406 If one was to guess, she could be off to make the second edition of Playboy. Depending on where you read, Bob exploded. She was gone shortly after. But who knows.