That's an interesting idea on its own. It's true that organizations which mutate towards survival may stop working towards the reason they were created.
In a sense, the difference between 'projects' and 'companies' reflects that difference you want. A project would be that social system that accomplishes its goals and then disappears.
I don't think auto-expiring laws would work towards the goal of avoiding corrupted organizations; there would simply appear an unofficial organization working towards recreating the same laws over and over.
It would be more efficient to differentiate more clearly what systems do cover persistent human needs (e.g. the country's Constitution) from temporary measures (e.g. subsidies aimed at a commercial sector).
A built-in deadline works best for the second kind. And for AI agents, it's likely that right now we'll be served best by always having them controlled by an expiration date and explicit re-creation, at least until we learn to properly understand and control how they behave.