Star Wars is a film that has dated well.
The intent being that Star Wars has not shown its age as much as other movies. I would think "hasn't dated" or "has aged well" would be more correct but I'm not sure.
In this context 'dated' means 'has become dated'.
Also, your original sentence could also mean: has 'retained that late-70s look' well.
'dated': from a time ago, and can be negative 'dated well': dated, but as a positive 'hasn't dated' / 'not dated': dated, but still seems contemporary 'aged' has become older, neutral 'aged well' aged, but as a positive
So, you were probably more right with original wording!