@Cornpone and Molasses and @CavRTO I grew up on the Jersey Shore, went to Florida for a job literally the day after I graduated high school and stayed there for 30 years. For years I lived without the most delicious delicacy on Earth, the Pork Roll Egg and Cheese on a Bakery Fresh Hard Roll. I was sitting in a diner I frequented down there regularly for years wanting something different for breakfast. I had never really looked the menu over carefully before.... lo and behold.... there it was..... only under the disguise of Taylor Ham, Egg, and Cheese. I yelled at the waitress who I had come to know fairly well "HEY! WHEN DID YOU PUT PORK ROLL ON THE MENU!!" She looked at me like I was talking Chinese, "the Taylor Ham?" She said, "It's always been on there dummy" Well they didn't have to disguise it by it's Latin name. Needless to say you know what I ordered. It was on a store bought hamburger bun, not a fresh hard roll, but still a little taste of heaven.
So, back to "y'all," Montgomery and Heinmiller's "Dictionary of Southern Appalachian English" (2021, U. of NC Press), notes "y'all" is pronounced in either the familiar plural nominative (formally YE ALL), or plural objective case (formally YOU ALL).