I expect JL-9G will only be used on land bases ( or perhaps only one land base ) to train pilots in take off over a ski ramp and to make a trapped landing. This will have necessitated a major increase in structural strength but to enable the aircraft to be used aboard ship will need an even stronger and heavier structure. Beside I think a shipboard trainer should have two engines. ( I know, T-45 ).It will be interesting to see if the new JL-9G will evolve into a single seat combat aircraft to supplement the J-11s on the new carrier. These inexpensive little aircraft could see a market in the 3rd world as 2nd or 3rd tier aircraft in an air force. There are many nations that still operate the F-5E (in its many upgraded forms) and the MiG-21 (in its many upgraded forms) that would be interested in this craft.
The aircraft is inexpensive to purchase and operate and can provide additional numbers to supplement better types like the Su-27/30 and the MiG-29. If it retains any of the advantages of easy maintenance like the MiG-21 it should be welcomed by many cash strapped government seeking an aircraft that can perform a military function and also provide pilots with the required flying hours.
It the F-5 was still produced today there would be nations that would purchase it. The single seat version of the JL-9G could almost be considered an F-20 of the MiG-21.