During some testing with Comment Mail Lite v161213, I observed behavior where a Comment Mail "All Comments" subscription did not get deleted even after the associated comment was trashed and then deleted permanently. However, there were several other "Replies Only" subscriptions that were deleted when their associated comments were deleted, so it appears this issue may only be related to "All Comments" subscriptions.
During some testing with Comment Mail Lite v161213, I observed behavior where a Comment Mail "All Comments" subscription did not get deleted even after the associated comment was trashed and then deleted permanently. However, there were several other "Replies Only" subscriptions that were deleted when their associated comments were deleted, so it appears this issue may only be related to "All Comments" subscriptions.
This needs more testing to confirm.