In "Serena cuts her hair", Pancham and Fennekin attempt to cheer Serena up. They then both watch as she shaves off her hair.
In "Why Serena isn't in Alola", Pancham and Fennekin more than likely accompanied Serena as she travels to the Alola region. This would mean that Pancham was killed in the Team Rocket terror attack on the plane.
- Though it has not been officially announced, it can be assumed that Pancham was killed in the plane explosion.