The framework of explicit "imaginary property" is new, within the past few decades. Thinking of copyright (et al) as general property rights leads to errant conclusions. Such as that at copyright expiration, the owner is forfeiting their "property" to the government. I refer to it as baseless because it's not modeling physical reality (information isn't exclusive-use), but backfitted based on wishful thinking of how some would -like- the world to operate.
Registering a work would be quite easy in this day and age - a hash for confidential priority, and then an easy upload to cement the registration. "Little Jimmy" wouldn't need to register anything until he decided to start distributing his game, and only then if he wished to take advantage of copyright.
Works being implicitly granted copyright is at the root of the problem with DRM.
A DRMed track is not a creative work, but a mechanically-created derivative of a creative work. Allowing the original creative work to remain secret while still allowing copyright on mechanical derivations of it creates the situation where the content creator can have their cake and eat it too, by releasing a crippled limited-purpose derivative with no intent to add the work to the public domain.
The crux of the matter is this - if creators use the law of the computational jungle to prevent full access to the work (to remix/port/etc) after copyright expiry, then why should members of the public not similarly revert to the law of the computational jungle wherein copying is Free?