One thing to remember is that AIM revision dates do not correspond to line change. John Z I believe, stated that line change could have taken effect several months before or after an AIM revision.
The service bulletin states that June 5 would be the cut-off date for the 2 piece fitting on the production line, but I am not sure how that would have played out.
Could be that test runs where mad before cut-off for drilling the 1/2'' hole and installing the grommet as this was part of an RPO and not a Fisher Line piercing.
Maybe John Z could comment on the time frame?