I'm southern, let me help. "Y'all" refers to a group of people. It usually means the group of people that the speaker is speaking to, but you can also define the group, like "y'all in the other room" or "y'all Canadians".

"All y'all" refers to the entirety of that group, as opposed to a subset of a group, which would be "summa y'all", or none of a group, which would be "nunna y'all".

I'm not a Nebraskan, but my daughter plays volleyball. She said it was a genuinely cool thing to see, and I'm sure it was a special experience for all involved. I would love to have been there to see it.

I don't know why you feel the need to comment on the article just to shit on a sport that you don't find interesting. You're allowed to not comment on things, especially things you don't care about.