This was not a true AC regatta. It was a "Deed of Gift" challenge.
It most certainly was a true AC regatta... Go to the AC website and look at the history of the AC and you will see that the LV Cup format is a new race format to improve the competitiveness of the challenger.
The "Deed of Gift" is the original governing document of the America's Cup. To challenge under the rules of the Deed of Gift is an AC Regatta in the truest sense of the sport (no LV Cup series).
Originally Posted by wikipedia
From the third defense of the Cup in 1876 through the twentieth defense in 1967, there was always one challenger and one defender, although the NYYC ran a defender selection series to pick the yacht they would use in the match. Starting in 1970, interest in challenging was so high that the NYYC started allowing multiple challengers to run a selection regatta among themselves with the winner being substituted as Challenger and going on to the actual America's Cup match. From 1983 until 2007,Louis Vuitton sponsored the Louis Vuitton Cup as a prize for the winner of the challenger selection series.