Apocalypse has many problems but I think one of its positive is that it set-ups the ideas in Dark Phoenix in this scene. Jean having a dark destiny, Xavier’s hope in Jean controlling her powers, and most importantly it shows that Jean has a deep fear that she will lose control of her powers and hurt someone. This is what makes her situation in Dark Phoenix tragic, it’s worst nightmare come to life. Founding out that she killed her caused her mother’s death by losing control of her powers and then Mystique’s death happens. Makes you understand why Xavier wanted to keep the pain.