Brees helping bring a sliders chain to NOLA...

Eh, you can probably forget them going to a medium-sized market. In-and-Out only does hyper-populated major metro areas like Dallas and Los Angeles.

There’s a school of thought out there that says Shake Shack is a better burger anyway. Two of those in the N.O. area.
Back when In-N-Out expanded to Texas, I read that they only open stores where they can have one of their factories nearby.

Being able to transport the patties to the restaurants quickly - contributes to the freshness and taste.

If that's still the case, it would explain their limited coverage area.

(I've yet to try Shake Shack)