I don't think that's enough. What if I'm writing a trilogy and it takes me two years per book. Some hack can publish a sequel before I'm finished.
Yup. The hack can't claim to be you though, so I don't really see a problem.
Or worse, what if a band only gets discovered after several years of playing smaller gigs, and just when they hit it big the copyight on their best album (usually the third) expires ?
Then everyone benefits from having their best album in public domain, and the band is motivated to make some more good albums.