The story clearly states Harry’s explicit interest in not attending school, so he wouldn’t have tried anything to change his sleep pattern for that purpose, and I doubt by the age of 10 he’d found any other important reasons to motivate sleep pattern changing therapy.
I also doubt his parents’ preferences matter, here, and even if they did prefer he change his habits, I doubt they’d press him into therapy without his explicit, cooperative, interest.
The story clearly states Harry’s explicit interest in not attending school, so he wouldn’t have tried anything to change his sleep pattern for that purpose, and I doubt by the age of 10 he’d found any other important reasons to motivate sleep pattern changing therapy.
I also doubt his parents’ preferences matter, here, and even if they did prefer he change his habits, I doubt they’d press him into therapy without his explicit, cooperative, interest.