When there is a cast departure, it's usually announced ahead of time. No such announcements were made this year. However, some cast members have remained mum until after the episode (Sasheer Zamata most recently), so we aren't certain that everyone will be back. I noticed Leslie Jones was getting a lot of attention during the goodbyes, which makes me a little concerned that she is making a planned exit, but no announcement has been made. A couple of things we do know:
- Kenan Thompson already confirmed that he will be back
- The standard SNL contract is for seven years. Aidy Bryant and Cecily Strong are hitting that limit right now, and Kate McKinnon will be partway through next season. The rumor is that Aidy and Cecily negotiated an extra year extension, so they will likely be back (though next year may be their last).