it's not about losing money. The issue is just not having airplane in action. Chinese govt can subsidize airlines for using Leap-1C [CJ1000A] but if Leap-1C C919 is out of service for 2 months due to lack of servicing, then you have to cancel flights.
I don't think the airlines will be overtly subsidised for using the CJ1000A engine.
At the beginning, I expect every domestic Chinese airline will be "required" to have a certain percentage of their fleet using the CJ1000A engine.
So every airline in China is equally disadvantaged with somewhat higher costs, which is passed along as higher airfares to the public.
From the perspective of the Chinese government, that is a good thing as higher airfares would encourage more rail travel instead. From a global perspective, higher taxes on the carbon emissions produced during air travel are coming anyway, and overall would be a good thing for the world.
And eventually, we should expect Chinese airliner engines to be competitive globally and therefore not need any indirect subsidies.