Let's look at facts.
Ole Miss has tentacles all over Memphis, that's not really an option. Plus geographic proximity to Ole Miss.
Tupelo gives you better access to Nashville and Huntsville, with direction shots to Birmingham and Memphis (even though it's really Ole Miss territory). And again, too close to Ole Miss.
Meridian gives better Jackson access and you also become the closest SEC school to Mobile and the western FL panhandle.
Hattiesburg is out, as USM is there.
Jackson is intriguing, it gives the state of MS a thriving capital city suddenly, but takes away from all the things Tupelo and Meridian give you. It also gets you farther away from Tuscaloosa.
If you do all the pros and cons, and consider that the only reason you want to be in NE MS is because we are leaking population to Nashville, Huntsville and Birmingham, I'd say the answer is the Jackson metro area, because then you have an urban center that would be attractive to many, many people. I think in 2023, that's the answer.
If you could go back to 1878, I'd say you never split with Ole Miss and put it in Oxford. But if that split happens anyway, I think you'd need to go Meridian like they planned originally. But now, I think it's Jackson, probably on the Rankin County side somewhere, as that gives you separation from Jackson State, Belhaven and Milsaps and outside the grip of Jackson/Hinds County.