The Season 18 finale of Grey's Anatomy finally saw Bailey choosing herself over her job. In doing so, Bailey prioritizes her family, mental/physical health, and joy over a job that as of late felt more thankless than rewarding. She tosses Meredith the keys to her office and essentially quits, though it's suggested that this is perhaps a temporary move.
In the Season 19 trailer, Maggie (Kelly McCreary) excitedly says to Bailey, "Are you back?" Her response is classic Bailey: "I heard about the new class." That's right, a fresh crop of residents arrives at Grey Sloan Memorial, but there is just one problem— these doctors-in-training are basically leftovers. No one wanted them, but who better to get them into good medical shape than Meredith under the watchful eyes of the doctor who trained her: Miranda Bailey?