This Ivy offers a required writing seminar for freshman. My kids’ colleges did as well. No one was exempt from those required classes because they were designed to help the students learn to be the kind of writers they needed to be for college. Kids came into the classes with varying levels of writing expertise. The course helped level the playing field.
It sounds like this student might have not done anything extra to get a better grade in this course…office hours study groups, writing center, etc. I would explore this with this student before blaming the HS.
In addition, the OP states that all of this student’s grades were less lofty than in high school…which is not uncommon for first semester freshmen…some of whom just need to learn low to do college…which is so much different than high school in terms of student ownership of everything.