I'm impressed that you found so much! On the other hand, given the timeslot Kissyfur was handed this year, you could argue that the generic "We Now Return" bumper was used for that show.
Few facts about the NBC's Secret Saturday Club (1989-90): a) These bumpers was animated by Craig Bartlett, who go on to make the famous "Hey Arnold" on Nick. b) The music is a version of *1989 Come Home to the Best, Only on NBC! fall jingle* (last season that they did that). c) Used from September 9, 1989 to September 1, 1990.
The demise of Saturday mornings on the Peacock 🦚 (NBC) could be considered a perfect storm of: (1) NBC relying too long on five cartoons (The Smurfs, The Snorks, Alvin and the Chipmunks 🐿 , ALF and until it moved to ABC in September 1989; the Gummi Bears) as their heavy hitters. (2) The replacement newcomers being extremely weak (The Karate 🥋 Kid, Gravedale High, Kid & Play, Yo! Yogi and ProStars, especially). (3) NBC News wanting to expand the Today show to Saturdays (the one day they did not air on; Today had only expanded to Sundays about 1987). (4) Lastly, the success of Saved By the Bell leading to NBC executives doing what most network execs do when a show is a huge hit: order as many clones as possible. Leading to the birth of Teen NBC (TNBC) on September 12, 1992.
