A technology startup has developed software that uses machine learning to predict which students are at risk of dropping out of university. The system analyses attendance records, assignment submissions, grade patterns, and library access to identify struggling students before they fail. University administrators can then intervene with targeted support such as tutoring or counseling. A pilot study at one university showed that 78% of students flagged by the system did indeed experience academic difficulties within the following semester. The developers argue that implementing this system across all universities would significantly reduce dropout rates by enabling early intervention. Several universities have already expressed interest in purchasing the software. Which one of the following, if true, most weakens the above argument?