Only if you assume that the movie picks up where the season finale ended. In my imagination the movie takes place some time after the events of the season finale, maybe one or two years afterwards. Finn doesn't neccessarily appear in the movie. It could be mentioned in passing that she has returned to Seattle, DB leaves for DC within the first few minutes and our original cast (minus Warrick) are the focus. We get one fantastic mind blowing case that has everyone working together to solve (but no mass shootings and no CSI's in peril). In theory the Nick Scenarios that stokesmyfire mentioned are possible. Mind you, Nick leaving a director's position to become a Supervisor is a bad career move and would not reflect well on him. I see the movie as a stand alone and not as season 16 Episode 1.