In examining the rest of the Directives I have on my desk, it doesn't look like there is an "A" version. It may be that the "A" version is the original version, but the original version doesn't have the cover page that the current version does, so it's not designated as the "A" version. I'm honestly not sure, and am happy to defer to my learned colleagues on this.
Where M1... appears in the text of the subsequent pages, it shows where M1... modified the text. The text you see is the modified text. I'm not sure what you mean when you ask if it should be replaced with the standard description on page 1 though. Could you please clarify?