I don't think we'll really see old Chinese ppl (meaning the boomer generation) stop working; from some boomer Chinese i know who have the option to retire, they would still prefer to continue working to make money.Well the so called demographic problem is too many old people not working, fewer people in the workforce to generate the wealth for their pensions, not necessarily an overall reduction in headcount, until they die the old people are still consumers! Automation will help the reduced workforce supply the segment of society that no longer works through increased productivity, So you are conflating 2 unrelated things and coming to a spurious conclusion.
I don't know if it's an indictment against the conditions where they were brought up in- poverty and famine and civil strife- or cultural industriousness, but i don't see elderly chinese people stop caring for their families or being a net drain on the Chinese economy. Even if they're not working they still provide invaluable experience and knowledge to the younger generation and help with taking care of the grandchildren whilst the parents are off working.
The only problem i can see is if these elderly Chinese retirees resort to gambling if they're not working- a colleague who lived in san francisco said these old chinese ppl would gamble their retirement savings away and be left with nothing. Thankfully, the CCP has laws and social safeguards against over-gambling.