Yeah it could be since copyrights have an expiration date before the thing becomes public domain. In order for, say, E.T. for Atari for become public domain, Howard Scott Warshaw would have to die and then 70 years later the copyright on E.T. would end. And that's assuming HSW maintained the copyright himself, and isn't held by Atari. I don't know how it works in the case of a company that can't technically die. If it just becomes 70 years and the author's life has no bearing on it, then it still would be 28 years until Atari's E.T. is public domain.
The length of time, IMO, should be shortened to just life of author+5-10 years.