A5 just means that they can make their own rules regarding scholarships and other things to benefit students. So they do that, but it all happens by consensus and coordination and agreement between those 5 conferences to keep things level between them.
But with the CFP agreement expiring in 2026, does anyone think that the Big 12 (or PAC12 or ACC) is going to have an equal voice as the B1G or SEC in determining postseason play or the like? At that point the B1G and SEC will negotiate with one another, come to an agreement and then tell the rest of us that we can abide by their rules and agreement...or we can choose to not be involved.