It was brought back the next year. As a result, Kelsey Grammer and Tyne Daly's guest appearances on Wings were nominated in the lead actor/actress category for sitcoms, which just wasn't the right placement. Whoever was a guest nominated in the drama categories would have been in the same boat as well. :confused:

https://www.tvguide.com/news/emmys-guest-cateogries/ So this article from 2016 seems to explain it pretty well. Basically, some members of the Academy were angry in the 1990-1991 season when the guest categories were handed out at the Creative Arts Ceremony and not during the main television broadcast, so as a response to that the categories were eliminated and guest performers competed in the supporting categories for the 1991-1992 TV season. The results were embarrassing and lasted only that year before the guest categories were returned; albeit with the addition of the categories being highlighted during the telecast in the following years.