You're right, but spending time with family and friends and being spontaneous and fun might be important to her, it gives you a sense of freedom,you feel young and alive. OP saying "no, we're going to to home and watch this movie as planned" would feel controlling to me. She probably missed out on going out, seeing friends and family when OP was controlling and needy as he says.

I get they had plans, but his gf doesn't seem to show interest in this movie, only that OP wants them to watch it. With most controlling partners, they want to stay in where they can have all of your constant attention. They usually don't want to go out and "share you", but they don't want you to go out and socialize without them either. It's emotionally exhausting and maybe now that they're past that, she wants to go socialize and go out on dates and do stuff together or with friends. You know?

Maybe she wants more romantic outings, or wants to spend more time with other people. Controlling partners usually isolate you from your support group and prevent you from socializing. Keeping and strengthening relationships with her support group and spending time with them might be something OP's gf is doing for her happiness so that their relationship doesn't slowly start to fall back into him trying to control her.