I think there is a key difference here. Insurance policies are contractual obligations to pay many years or decades in the future based on assumptions freely made by the writers. If those writers mispriced the contract, it seems a little strange to back out of it decades later by saying we made a mistake. I'm not sure how rents work but usually they are annual leases and increases are stated on the new year. Same for medical premiums.
Personally, I made pretty good money from GNW. As I do some research for LTC policy, I found there is no cash value for long term care policy. Just imagine, you bought the policy and pay the premier for 20 years, all the sudden, they want 100% rate increase, you are at 75. Yes, it is legal, but pretty bad!