The problem is that these are not legally mandated, so they can shut down (as UltraViolet did). If the ability to move the licence to another platform is mandated by law as a condition of continued copyright protection, this problem would largely disappear.
In practical terms, the logistics of many-years-later refunds would be unwieldy at best. Do the purchase records still exist? What if I no longer have that credit card or email address? How can you prove you're the heir of the deceased? What if I now live in a country where the "deletion" status is different? And how could you stop all the scammers who smelled free money?
Alternative: The gov't randomly picks 24 citizens from a pool of applicants who reasonably prove that they were harmed by the deletion. Those 24 are given legal authority to fiat-revoke all copyright protection on a "reasonable and proportional" number of the deleting corporation's currently copyrighted works. Or upstream of them, as "appropriate".
Similarly, we should put in a law to force consumers who post bad reviews to prove they actually transacted with the business. If they can't, they have to go to every person who saw the review and personally retract it.
Can't figure out who saw it? Tough. It's up to you to figure out, or else it's illegal and they get 5000 years in prison for every view it got.
To put it in perspective, I bought Get Him to the Greek on Prime video shortly after it came out.
A month later, the "exclusive broadcast rights" changed, and I was no longer able to access it.