Ok, I just found this on UCI site under Common Application Errors:
“Applicants fail to list ALL schools attended since 9th grade: Even schools outside the USA and even schools where course work may have not been transferable or completed must be included on the School section. This is important information for evaluation purposes and failure to list all schools could result in delay of the admission process and/or cancellation.”
Either way, it probably doesn’t warrant an email.
https://www.admissions.uci.edu/applicants/faq.html#common_errors