What would change if old software had to earn another interval of life?
Software accumulates by default. Interfaces remain available, permissions stay open, and temporary state becomes part of the system because nothing required it to leave.
Working distinction
Expiration is not the same as immediate deletion. It gives an interface, permission, or piece of state a time when its continued use must be reconsidered. Renewal then becomes evidence that someone still understands its purpose.
This reverses the usual burden. Retention becomes a decision instead of the absence of one.
Questions to carry forward
What should be allowed to expire? Who can renew it? What evidence should renewal require? What happens to copies in logs, caches, backups, and downstream systems? Which promises cannot be given an expiration date?
An expiration mechanism is only useful if it makes old decisions visible before it removes them.