I just want to say one thing( maybe more :) ). Ok, they mention Mer's kids. But what about Tuck, Baley's son? How long has it been? Miranda was bothered because she couldn't have sex with her husband since Jackson was in the other room. But what about his son?
I really think they should have stopped with s10. Yes, the show is still enjoyable but this is not the show we fell in love with 10 years ago. That's not the journey we signed for. We will never get a satisfying ending because the past has been erased. Even Derek's death was less powerful compared to season 6 finale. Do you know why? Because there is nothing "old" left. Yes, Derek died. That should have followed with scenes between Mer-Cristina.
We have little connection with this new set of characters, so why should we empathise with them since the journey has started many years ago.
To me the real Grey's ended with S5. The show was about 5 interns navigating life. That was the focus. That was what made Grey's Anatomy the best show on air.
Sorry for the rant