Addressing a mixed group of boys and girls, it used to be guys and gals. Now it’s just “you” guys.
In all candor, the phrase “hey…guys…” or “listen…guys…” has always come across as code for “ya dummies, let me explain it so a child can understand it.”
One former coworker ALWAYS used that phrase before lecturing us.
Back in the day, it was ok in business to say “between us girls” before divulging some secret-like info…even if it was all guys or guys and girls.
If we were in Pittsburgh we’d say Yinz.