A bit of a shame that the C919 isn't mature enough to fully take advantage of Boeing's current issues and Airbus's massive backlog. It's still gonna benefit from it greatly no doubt, but imagine if there was hundreds of C919s flying for years already and COMAC being able to make dozens of c919s a year when the current issues that plague Boeing is happening. They could made a really big push to foreign airliners. As it as, they're struggling to produce enough for the Chinese market as it is and the fleet still hasn't flown enough to really prove it's safely record to the public.
As it is I fear that by the time the C919 is being mass produced in sufficient numbers and has enough air-time to prove it's safety record that it's attractive to even western airlines, Boeing could have repaired it's reputation by that time and Airbus will no doubt have greatly expanded production to cover it's massive backlog of orders.
It's a shame, it's basically the perfect time for COMAC to enter the market but they're unable to take full advantage of it, maybe if this incidents had happened 5 years later...