I think it is a slightly different thing. In Elizabethan England, intellectual property rights - if that term can be applied - applied mainly to the live performance - the authorship of the text was less important, and as a rule it was collective i.e. various people contributing to the final version or perhaps borrowing liberally from other people's texts.
The same can be said about other arts as well e.g. painting. Usually several individuals were involved in the physical act of creating them, and the master would finally sign his name at the finished product.
So the Shakespeare's fame came mainly from the fact that he was a producer of a collectively put together show rather than an author of the text. Today we are simply projecting our own ideologically motivated notion of intellectual property rights and are amazed to discover that Mr. S was not the sole author. But this is more of function of that old ideologically motivated ruse that intellectual property rights is a necessary condition of creativity. It ain't - neo-liberal hogwash notwithstanding.
Wojtek