Didn't realize this was such a niche idea that you'd be downvoted. I don't think anybody really benefits when a child or grandchild coasts through life on the basis of their ancestor's success.
The current law is still extends the copyright of a work until a time after the author's death. So if one wished to hasten the expiration of those rights, the motivation still exists; although perhaps diminished by a 70 year wait.
Honestly, I find it difficult to understand why a fixed 40 year term isn’t long enough to benefit from copyright. Trademark is already indefinite, JK Rowling is hardly going to be meaningfully harmed if someone publishes a work based on the first Harry Potter book in 2037. Less wealthy authors generally need to keep working anyway. Publish a hit at 22 and perhaps it’s time to start saving for retirement just like everyone else.
Which are life imprisonment for murder. Not some magical "my children must be fed millions without ever working until 70 years after my death".
Seems a lot of risk and effort for a small chance of profit.