According to ECHA,"the text has been throroughly revised amending both content and structure." Changes to content include improvement of the "overall coherence" and to create a more focused document that helps companies avoid "unnecessary testing." Duplicative material covered in other guidance has been removed and/or made more consistent. Two new sections have been added to make the document clearer, including more comprehensive discussions of the data sharing process for phase-in and non-phase-in substances. Additional new sections cover the "data sharing dispute processes" and "post-registration data sharing obligations."
More information can be found on the ECHA site.