When the assets are liquidated, the ex-employees are paid first along with all the other liabilities. The company will pay. If they don't have the money to pay off all of their liabilities the shareholders get nothing at all. Not one cent. This is accounting 101 here.
If the shareholders really thought the company could survive they could have simply paid off some of the liability and avoided bankruptcy. Instead they chose this route.
I can't claim to know how bankruptcy laws work in France, but in the U.S. secured creditors get paid before priority unsecured creditors, which include employee claims for wages. So employees get paid last, since any corporate debt is sure to be secured. This is a company with only $600k per year in revenue that has already filed for bankruptcy once, so I doubt it is standing on a pile of cash.
If the company had the money to pay these severance payments, they wouldn't have had to declare bankruptcy as soon as the courts ruled against them.