The issue with stuff like this is inheriting all the funds held in the old contract. I guess a hard fork can do it. There's also the issue of trustworthiness of the smart contract owner. Trustworthiness in general is a huge issue in the crypto world, because if you can get away with something you can do it pretty much instantly and irrevocably (without another hard fork anyway). There's a chance that if you share a vulnerability that would allow one of the contract owners to take advantage, they will just do it and run. Plenty of cases of previously-trustworthy crypto people seeing an opportunity and disappearing with a lifetime of money.