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.
I think the difference here, is that you’re not talking about a collective, but instead two different individuals. I agree with OP on this one, and I think “guys” can refer to a collective of humans.
Is it right? Probably not. Do I think of just a bunch of men when someone says “come on guys”? Not really.
If it refers to all genders in some contexts, but only to men in others, then it isn’t gender neutral.
It isn’t gender natural only in some cases
Waitress is only women, but waiter can mean either.