I love how y'all in the singular sense demonstrates a linguistic principle towards singularization that I had read about but never seen in action. Where I live today in Michigan, y'all is definitely received as plural, understood as an abbreviation of you all. But when I lived in Alabama, all y'all was the much clearer plural choice.

By the way, I don't know if you've seen this trend yet, but the youngest generation are starting to use bro as a gender-neutral term. I've seen YouTube videos where teenage boys call girls "bro" in direct address without the slightest bit of irony, and without any sort of negative reaction from the girl in question. I don't think I've seen any evidence that girls are calling girls bro, however, which would probably be needed if the term were ever to be fully accepted as gender neutral.