Was the random Saturday in December Candlelight? Of course they blocked it out to avoid traffic messes on Main Street.
And yes, with the Flex Pass, Disney gets to decide how many reservation spaces are made available. If Marketing wants a crowded Star Wars Land, then of course, they can make more spaces available...
I don’t remember the exact date but there have been a few Saturdays and Sundays blocked out this past fall and winter. Just seemingly random days other than the fact they are Saturdays during the busiest time of the year at the resort. Still not as noteworthy as the opening weekend of ROTR. So I wonder how much of this is manipulation and if there is the possibility the majority of people are still scared of opening day / weekends and just may be avoiding the park?