Okay, not a Southerner myself, but my understanding about mac and cheese is that it is/was an African-American TG tradition. I think the “I never heard of this” comments speak more about cultural division than that the list is totally wrong.
I mean, any time my students at the majority AA college I used to work at wrote about TG, it was full of foods with southern roots (as their families were usually originally from the South), and they always listed M & C prominently.