The current production rate will stay the same forever?
Right. Target is 150 a year by 2028. China's need for narrow-bodies is over 8000 over next two decades. It will take 50 odd years to just meet domestic demand even at 150
Obviously, a large portion of that demand will be supplied by another Chinese plant -- the Airbus one at Tianjin.
COMAC doesn't need to export to become a massive success. But neither does BYD. So like BYD it will export if conditions are right and that is made easier with a EASA cert.