Fetal surgeon Arizona (Jessica Capshaw) left Grey's at the same time as April Kepner, leaving Seattle to move to New York, where her ex-wife Callie (Sara Ramirez) resides, so that their daughter Sofia could stop splitting time between her parents. Like Drew, the decision for Capshaw to leave wasn't her call, but at least in Arizona's case, her exit made a little more sense. Throughout season 14, Sofia had been struggling and acting out, clearly missing one mom while unwilling to leave the other behind. Arizona's decision to put her daughter first and uproot her life so that Sofia could feel safe and supported was a beautiful way to end her arc, especially considering that originally, Arizona didn't even want kids. Plus, judging by the text messages she was exchanging with Callie in her final episodes, it looked like it might finally be the time for the two star-crossed lovers to reconnect for good.
While Arizona's exit felt pretty well earned, it would be easy enough to find an excuse to bring her back. While it's hard to see a scenario where Arizona would come back to Seattle for good, as one of the only fetal surgeons in the country, the former Chief of Pediatrics would be the first one any of the doctors at Grey-Sloan would call to assist with a tricky case that could make use of her unique skill set.