I'm not sure where I stand on this decision specifically regarding Arroyo however I would like to weigh in regarding the extra year of eligibility.
In NY state we had 5 years to play 4. I find it hard to believe that this rule was put in place so that students could intentionally fail classes so as to be an extra year older and thus gain an advantage. Rather, it seems more likely to me that the High School League recognized that there will be times in athlete's lives where they may be struggling academically and in those times they should put their full resources towards academics. That being said, if a student is unable to "right the ship" then they would not be penalized and lose the year of eligibility.
South Carolina's rule as it stands punishes students who may decide that they are struggling in school and need to dedicate the year to their academics. It says to students, even if you're struggling in school you have to play this year if you want to use all of your available eligibility. The student's dual focus results in the student's academic standing to suffer even further.
If the rule were changed would we see a dramatic increase in the number of athletes intentionally failing in order to be a year older? Certainly not, those who would employ such a rediculous practice are currently doing it at the 8th grade. The rule change would simply allow more flexibility for rare situations like this that occur.
Sad to see the end of this student's high school eligibility, however, as stated before, division 1 schools who were interested in this student will continue to be. Most of their signings for the next season have already occurred and those who remain interested will gladly travel to view a club match where they can watch several potential recruits all at once. The real losers in this scenario are Arroyo's teammates who have lost out on a significant cog to their team (as well as the free publicity/recruiting that they would have received from coaches coming to watch Arroyo).
Good luck and best wishes as the season begins