As I generally understand, only large media distributors are able to distribute and generate revenue in a timeframe as short as that. Small independent artists and creative groups would probably be unable to generate any meaningful return in three months. Sure, they can get exposure in three months, but by the time that happens, they already lose copyright.
Add to that the fact the only way say, a band, could keep a copyright going is to come out with an album every three months. Impossible to make anything worthwhile, and the independent scene would drown in a glut of crap.
A copyright law like this would only be workable to big media groups that can do a broad release and generate revenue quickly, and if you are unable to release on that scale, you'd get slaughtered. I'd be fuming if some MP tried to introduce something like this in Canada. I might be missing some points in regards to this, but it seems that copyright like this would be a death sentence to small artists.