Being asked about playing Batman specifically, it’s understandable if Gosling doesn’t really want to say anything, considering it’s not entirely clear if that role is actually available or not, but when it comes to superheroes in general, one would think he has a feeling.
Ryan Gosling had to have been asked this question before, you’d expect he’d have a stock answer, even if it was a non-committal one.
Either he’d like to do it, or he’s happy doing other things.
It’s a little odd if only because the “superhero question” has to be the single most popular one asked of any actor that isn’t currently involved in making superhero movies.