Just looked it up and the entire first page of searches is about how ‘guys’ is masculine and insensitive to women. I disagree. I think the masculinization of the term is like an unneeded extra filter placed over ‘guy’ but the term itself is innocent. Guy Fawkes was a real person. He did something that caused him to be a symbol of the common person. There is nothing gendered about that. It’s the patriarchal culture that then assumed ‘common person’ refers to males. When I think of Guy Fawkes, it is his actions, not what’s in his pants, that is important. So, while there are many needlessly sexist and sexual phrases in English, I do not view ''Guy" as one of them and, instead, view it as a victim of the patriarchy just like you and me. It isn’t an inappropriate phrase to change or remove, it’s one to reclaim for all people; which is exactly in the spirit of the symbol of who Guy Fawkes is.
People argue too much about definitions instead of just asking the other party to clarify when they’re using a slightly different definition.
Context is also very important.
Reclaim all you want, while respecting people’s boundaries.