If they go bankrupt it's dobutful they would zero out your miles. They could always end the program, but if they pull through they want their loyal customers to stay loyal. If they go bankrupt and are liquidated the buying airline would probably allow a conversion into their program as a show of goodwill to loyal customer they hope would become loyal to them.

While it could happen it would be a major PR nightmare if they did and would probably send them into liquidation as loyal flyers looked elsewhere.