Doesn't that just give an incentive to labels to use products with ever shorter life though? Vinyl might be hard to look after, but if you do, it will almost certainly last longer than CDs.
Following this logic, we'l start to see formats designed to last only six years (when the Limitations Act means you can no longer meaningfully complain). CDs/DVDs can easily be made using a degradable layer with a fair degree of control of when it will expire. In a few generations, people might need a whole room in their house to store the jewel cases of CDs they've inherited, which stopped being playable many years before, but have to be retained to prove ownership.
It's a hard problem, but it needs a solution.