I thought the TX plural of y'all, is "all y'all"
Y’all: Regional Dialect, 2nd person & 2nd person plural, familiar form. (Cf. German, Sie / Du) I think all y’all just acts as an intensifier.
I would listen to a Texan saying Y’all any day over a N/Y or Jersey “ Hey, youse!” any day.
Meyer agrees with you.
I’m not from Texas so my memory was incorrect.
But that would make Trump saying it my way more conclusive.
I’m a 5th generation Texan and I have never heard anyone say “all y’all.” It makes no sense.