Copyright protects already executed ideas, stripping that protection down to less than a decade would be completely unhelpful.

It technically means the government needs to pass a very high bar before it can restrict any kind of speech, that bar being strict scrutiny.

Of course, the view of the public and the court historically has been that blocking union busting activities has passed strict scrutiny, since it a) is justified by the government’s interest in preventing the kind of violence that occurred when union busting was allowed, b) doesn’t restrict actions outside of union busting, so it’s narrowly tailored, and c) is the least restrictive method yet proposed, only other method I can think of is compelling union membership for everyone.