> Some of these are colloquial, but their existence also points to the fact that there are groups that weren't served exlusively with the gendered "guys".

Most of the replacements you cited are regional:

- Y'all is Southern/AAVE.

- Them is third-person, whereas "you guys" is second-person.

- "Yinz" is from Pittsburgh.

- I'm gonna throw in "youse," one of my faves, which is from New Jersey/Philly.

"Guys" is clearly gendered, whereas "you guys," I'd argue, generally isn't--especially in the Northeast US. I frequently hear cis women refer to groups of entirely cis women as "you guys."

This isn't meant as a view of what the ideal state of the English language is (bring back "thou!"), but these discussions frequently involve people talking past each other, and conflating "you guys" (second-person plural, arguably gendered) with "guys" (third-person plural, usually gendered). Effectively replacing "you guys" is a more challenging task, since there isn't a universally agreed-upon alternative, at least in the US.

I'll leave it to others to figure out what that alternative should be, though I will note that I, as a WASP from the Northeast, sound completely ridiculous saying "y'all."