As I understand it each document referes to a specific revision of silicon.
For each revision of silicon they will update the errata document with new revisions so if you look at Rev B6 silicon errata it is on document revision D.
Rev B7 silicon errata is still on document revision A.
For a given revision of silicon you should refer to its specific errata sheet and not all the previous silicon release errata cumulatively.
I might add that if the document is on Rev A it probably means they've yet to discover some issues with that release of silicon