If they are using SmartX to combine/mirror the 3600 system to the 9600 system then the core itself is already 9600. They could turn every site over to 9600 right now as far as the zone servers are concerned, the problem is swapping out Quantars, backhaul upgrades, among other things.
The ASTRO system upgrades allow for a greater number of sites in a system, greater number of channels per site, etc. Strictly a backend update most of the time.