Pro's and con's can be stated for either case, and are specific to an organization's needs. Some use review/stability dates for this (often outside of the document, such as ISO), while this way amends/apends the actual document revision identifier (which introduces some referencing problems), and might account for errata/corrigendums without being clear on it (ISO uses a to me inconsistently applied system of amendments and corrigendum, with strange numbering (sometimes starting at 11). I'd be hard pressed to push anyone on putting in more effort then looking at the summary, and simply consider it an indication of the date that the most recent review for suitability has occurred. If it was important in their eyes, it would have been a revision. I don't know about that specific standard, but I've never worried too much about Reaffirmations. If it would have made a difference in decisions you would make, it would (should) have been a revision. TLDR don't worry too much about reaffirmations.
