Then they shouldn't retain the patents, copyrights, cash, or any of the other assets. If corporations want the benefits of immortality, they need to accept the drawbacks.
If the company signed a 100-year lease 30 years ago, should it no longer have to honor it?
If the company agreed to pay pensions to its employees 30 years ago, should it get to stop paying them?
If the CEO of Chrysler retires, can I stop paying the loan on my car?
The point of a corporation is that it's a durable entity (NOT a person, but a person is a good analogy much of the time). That's why corporations can own property, be insured, get loans from the bank, and otherwise enter into contracts -- because there will be an entity there tomorrow that will be accountable for those transactions -- regardless of who owns its shares or who is on the payroll.