The NCAA governs conferences at large. They make some rules for college football that will be enforced among all conferences. How those conferences conduct their individual conference is up to said conference. For instance, the ACC said you could play 1 non conference game this year if that game is played instate. Other conferences felt otherwise. The ncaa had 0 say in that decision. Conferences still get to govern their conference. The ncaa can say you get a 1 time transfer. The sec gets to say you can’t transfer from an sec school to another. The sec may change their rules when the ncaa does. But, the fact is that the SEC gets to govern how intraconference transfers will be treated. Here is an article about this year where Sankey says this rule change is in light of Covid and not an endorsement of these conference transfers. Doesn’t sound like someone who is willing to change his mind on this even when the NCAA allows a 1 time transfer. It is like the federal government saying pot is illegal and individual states deciding if it is illegal within their boarders.
SEC grants eligibility waivers to some transfers