Does anyone know what aircraft will be used for the LA flight?
Airbus A220-300
The A220 is a home run for airlines in that market. Since the regional jets are at the edge of range for a flight like that, most airlines have to run a plane that's about 150 seats, which makes the economics tough. The A220-100 (at least in Delta's config) seats 108, and can make the flight with ease.
Now, I hadn't heard the reason JetBlue dumped JAX-LAX - the pilot thing absolutely could be the reason.
In terms of routes I want to see JAX get, tops on my list would be Delta running a JAX-SLC flight. They likely won't add while SLC is a little gate constrained (they're at a weird phase in their airport rebuilt and are using bus gates for some flights), but this would be REALLY nice for west coast connections.