I don't think I knew Sandler was fired from SNL (along with Farley). Not sure if it was Lorne's idea or NBC's. I read that some people (ex. Garofalo) had complained about the unprofessional atmosphere at the time. You could tell that this stung Sandler, and is the reason why he took so long to return.
http://nymag.com/arts/tv/features/47548/