For what it's worth, this article is omitting a glaring truth... the real reason for the cancellations was flight attendants. I don't know why the news media thinks "crew" means just pilots.

Many airlines this last weekend offered incentives to FAs because a high number called out for this brand new holiday called "juneteenth".... it's some kind of black holiday like kwanzaa from what I gather. And yes, that is why there were so many cancellations. Spirit paid their FAs 200% this weekend, Southwest marked it a "critical weekend", etc...