I think the general theme here misses the mark. McWhorter obviously wants to talk about the interestingness of genderless, though seemingly gendered, pronouns in his essay. So much so that his dismissiveness of "y'all" seems too curt, and I think it's a mistake because the regionalness of "y'all" over "you guys" reinforces his narrative.

I also always raise an eyebrow when a linguist is pining for a universal familiar third-person plural, which is noticeably absent from Spanish as well: "vosotros" vs "ustedes." I suspect that the regionalness and third-person familiar pronouns might simply go hand in hand, as they are an in-group signaling mechanism, and it's a bit rare to have large groups who you are close with who aren't part of your region.

I grew up in Austin. I use "y'all" and "howdy" regularly, even more so than when I was young. That said, I feel like Texas Monthly "defending" the use of y'all as a potential universal term is entirely unnecessary. Again, there really isn't a need for a third-person familiar pronoun that isn't a natural one to use, because the point of third person familiar is that everyone in the space is comfortable with each other. The only reason why a formal version of this would ever be necessary is to have some sort of formal version of an informality... which makes little to no sense at all.

Embrace the informality of colloquial third-person familiar pronouns. Embrace "y'all," "yinz," "you guys," "youse guys," and all the rest, because whenever you're on the receiving end of the pronoun, it means you're with someone who is trying to be friendly.