kraftie and webplodder have said what I was about to post, particularly webplodder in regards to being a woman having to be careful who you approach. And also about a movie theater/cinema not being like a social situation such as a party or friends gathering. It's a bit more unusual and not really the "done thing" to walk up and start talking to strangers after a movie than it is to walk up and talk to strangers at a party, a bar, a club, or other gathering, where it's acceptable. Personally I would not do it.
I don't go to movies much anymore as it's too costly, but during the time when I went a lot, I always went by myself, and only once did someone ever start chatting to me afterward. It was a woman (I'm a woman too) and was at a matinee of a chick-flickish drama. I think what happened was as we all left the room, there was a kind of ""After you" situation passing through the door, and so we laughed a bit and then she said what did you think of the movie? We exchanged a few comments walking out to the lobby then said bye bye and that was it.
So, that chat really only initiated because of one of us paying a courtesy of holding the door for the other, or something. It wasn't like one of us walked up to the other person and started talking.
I would say in very general terms it would seem a bit odd to do that, and would be hard to do skilfully even for an NT without seeming a bit forward, or having the person wonder what you want from them.