The confusion lies in the fact that 100% of all matriculated students are required to submit their board scores (assuming they took any) - whether or not they were considered during the initial admissions process.
This is consistent with the university’s most recent Common Data Sets as the numbers of enrollee’s who submitted one, the other or both the SAT and ACT match pretty closely the total number of people in the freshman class.
The FAQ from which the OP’s quote was lifted, concerned the question whether Wesleyan preferred one test over the other and should have simply answered, “No.” and left it at that.