re: Besides more hardware, what makes a recruit from Louisiana go to a hated rival?

If you are talking about actual student athletes it is Gen Z now, not Millennials. The youngest Milleannial athletes are not in college any more except for a few and none are recruits. As far as the coaches and parents, some are the older Millennials and most Gen Xers. So it is not really generational. It is social media manipulation more than what generations think.