Yes, the takeaway from this is not that 2021-22 is an outlier situation but in fact it's not so different from average. Since this is a recurring event, that green average line tells us that it should be planned in the future for late February or March. The Kachina chair is one of the greatest terrain pods in North America. It's been there for 7 years, open by Jan. 20 in two of them but by Feb. 20 in all but that worst ever 2018 season.
Late Feb / Early March is usually the national gathering. Like to space the gatherings so the attendees have a job to return to afterward.
Even without Kachina, there are lots of terrain open in a average year. Just don't ski over the rocks. No big deal.