Mountain Creek does that all the time. I think smaller mountains that don't have as much natural snowfall groom over fresh snow regularly in order to establish a thicker base which will enable them to have a longer season than if everything were left wild. Also, speaking from a MC perspective, the type of skier/snowboarder they normally get doesn't like or even know how to ski in loose snow.
i would bet its much more the latter then the former. most of these bigger (in terms of snowmaking) little areas close because of lack of customers, not base. Wawa doesnt need to groom to extend their season, they do it to keep the majority happy. there are alot of groomed pp cord lovers out there.
sundown, otoh, leaves most of their stuff untouched for the masses to fall in. you gotta love that approach for a little area.
and they'll close with plenty of coverage. people just dont think about skiing much in april anymore, especially down here.