Those are both Saturdays and 3 new things just opened at
Disneyland less than a week ago, so lots of magic key holders want to visit. In addition, I assume the impact to those Saturdays comes from a greater number of keys being eligible for entry on those days. Believe keys are blocked out Feb 18, March 18 and March 25, and there is still magic key availability for Inspire keys those Saturdays. You see no or limited magic key availability for all the other Saturdays through the end of March though when both Inspire and Believe keys have eligibility on those dates.