The Guru Granth Sahib exists today in a fixed printed form, and behind that form is a manuscript history that is actively studied and in places contested.
The compilation of 1604 was written down, and a manuscript associated with it has been the subject of sustained examination. Other early manuscripts survive, and their relationships to that compilation, and to one another, are the central technical questions of the field: which copies derive from which, what the differences between them are, and what those differences show about how the text was assembled and settled.
The second stage, in which the compositions of the ninth Guru were incorporated, produced the recension that the printed volume follows, and its association with Guru Gobind Singh is what gives the printed text its authority.
This is a field where scholarship and community authority meet directly, because a claim about a manuscript can be heard as a claim about the scripture. Work in it has at times been controversial for exactly that reason.
The atlas records that the manuscript history is real, that it is studied, and that specific questions within it remain open. It does not summarise particular scholarly positions on particular manuscripts, because those positions are contested and a reference work stating one of them plainly would be taking a side in an argument that is not concluded.