If society were a bit more empathetic, we wouldn't need to call it empowering, it would just be what she decided to wear. The problem with our own culture though is that even fashion is dominated with certain appeals to male sensibilities which are a result of being raised under patriarchy. If she wore a hoodie to the event and that wasn't part of the character she was portrayed as, she would be ridiculed. That's the real problem.
Also, making assumptions about her as she would exist in a videogame is far more problematic, given that you're hypothesizing sexism which doesn't exist.
I agree with your first paragraph (and only, not the second because of the current state of things, what he said was true). In this particular case especially - she may have an image to represent but that would be her choice as well - there is also a difference between a hoodie and something more modest. There are nice classy dresses right, she seems like she can afford one to fit if she wanted to?
The point about patriarchy is interesting as well. Is there more to that?