It's Tier 3 at best. I don't see the big deal. Great season, yes, but they wanted more, and lose a ton. It's not like it's a sign of great things to come or anything.
Tier 1 is a national title, obviously. This gives you a good 10-15 years of staying power. You're considered a blue blood now.
Tier 2 is a conference title/playoff berth level. Probably about 5 years maximum of staying power.
Tier 3 is your typical 10 win season or so, 10-3 or 11-2 with the Big 6/NYD bowl win or loss. About a year's worth of respect, and that usually comes with excuses. You really need to follow that up with another good year to have any staying power.
So basically Ole Miss is not taking some next step or anything. I mean look at what happened to them in 2015, they promptly followed that up with 5-7.