My understanding is that if copyright is used where it does not apply, one could rule that it is a common practice.
Which if I'm not mistaken, means copyright (in what is currently a patent sense) would be awarded retroactively to published designs.
That would be the poor mans patent, which is all good, and would require sharing to avoid the broken patent system.
But then we would have a lot of shared designs, that we could not use commercially, with comically long expiration's on them.
In the interim, what are already shared designs? Prior art to a new concept in copyright law, or to patent law.
With one being more lax and more protective, it could go both ways.