WARNING! This article contains minor SPOILERS for That '90s Show season 1!One line from Ozzie in That ‘90s Show season 1 proves that a spinoff following Red and Kitty’s youth in a That ‘50s Show spinoff would actually work. While That ‘70s Show did technically have an indirect spinoff with the canceled sitcom That ‘80s Show, it was virtually unconnected to the main story. As such, That ‘90s Show is the first official spinoff, with its popularity and success on Netflix increasing the likelihood of That ‘70s Show's franchise being expanded even further.

https://screenrant.com/that-90s-show-50s-red-kitty-prequel-prove/