They’re being overly sensitive, in most contexts guys is considered a gender neutral term these days. English is just dealing with the slow loss of gender from the language and it’s reached the point where there are so few instances of gendered words left that the ones that are stick out and feel a little awkward. Or like in the case of the parent post where people fixate on the linguistic fossils left in the language and decide to take offense by intentionally interpreting phrases in anachronistic ways rather than modern usage.

It’s the same in the US as well.