As you now have learned, the superspreader is the individual(s) who spread the virus to a large number of people. The event is where and when he or she did the spreading to many people.
We know you the term incorrectly because the Lake of the Ozarks Memorial day event is not yet a super spreader event. (an appellation you gave it which it has not yet earned.)
We have to see how many people were infected.
Yeah.... if your "superspreader" individual stays home then they spread COVID-19 to no one.
Once again... for COVID-19 a superspreader refers to an event as a location during a designated time.