Who said anything about organizing or packaging? Just put the code up on Github with a reasonable license and walk away. Running and maintaining is of course still a problem, but you can hardly expect a company that is out of business to do that.
I completely agree that open sourcing the project does not guarantee that the project will continue to function. I also think that after a company goes out of business they have no responsibility to keep their project functioning. Once they open source it, anyone is free to put in the work to keep it going and I can't think of a better guarantee a company could reasonably give.