Yes you certainly may. I am not sure, however, if they actually have a Reception on the 3 day cruise. I know they did on the 7 day cruise. I would bring along the DVC member card, just in case. There are also several presentations open to everyone that showcases DVC membership and its benefits. Similar to the member update held at OKW and BWV weekly. I try to go to anything and everything that is DVC related.
One of the highlights of the cruise was to stand up at the DVC presentations and tell everyone that we only paid $75 for our cruise. Of course, there's the matter of 440 points and the dues, but I figure that that money is already spent so it doesn't count. We had a great deal of fun at the DVC reception and at both of the DVC presentations.