That is just how she set it up for herself. The only thing different in the Wendi Plan and Flex points is SET POINTS ON SET DAYS! She came up with the concept of Flex before W/W did. She took her total points (from the minimim and maximum ranges) and divided up so she had a different number of points on different days. The SuperHigh day only problem I could see is if you use a lot of simple carbs or sodium laden foods that would cause a 'false' waterweight gain.
I have had super high days (50-65 points) the day before weigh in and still shown a very good loss because of how I used my points for the week. And it may or may not show a gain from this SHD.