Issue
Any email notification that uses sc_req_item.itil email template will not display the comments.
Release
All releases up to New York
Cause
This is happening because in OOB sc_req_item.itil email template comments are denoted by ${u_comments_and_work_notes} in the email body.
Resolution
The comments in the email template can be modified to ${comments_and_work_notes} and used.
This has been fixed in New York release.