So a guy wrote a book in 2021 and made loose leaf prints of it and I have one of the loose leaf prints. The book at that time didn't have any copyright attached to it and people were freely photocopying the book and the author was fine with that. However in 2023 he got the book published and now it is copyrighted. Obviously photocopying the published version from 2023 is illegal, but is it legal to continue making photocopies of the original 2021 version? Although I don't have the 2023 version it is probably almost exactly the same as the original with minor changes such as fixing grammar errors.
The author holds all the exclusive rights of copyright in the 2021 work, subject to licencing, assignment, or fair use or fair dealing.
The dominant copyright paradigm in the world is the regime established by the Berne Convention and agreed to by 181 of 195 countries in the world.
One of the terms of the Berne Convention is that "enjoyment and the exercise of these rights shall not be subject to any formality" (art. 5(2)). This is known as the principle of "automatic protection."
This principle is reflected in domestic legislation implementing the commitments of the Berne Convention. For example, see Canada's Copyright Act, s. 5. It specifies that copyright subsists "in every original literary, dramatic, musical and artistic work... if ... in the case of any work, whether published or unpublished, including a cinematographic work, the author was, at the date of the making of the work, a citizen or subject of, or a person ordinarily resident in, a treaty country."
Thus, it is it probably false that "[t]he book at that time didn't have any copyright attached to it." The author holds all the exclusive rights of copyright in the 2021 work, subject to licencing, assignment, or fair use or fair dealing.