So if i understand this correctly you want to send the same modification reason for a separate order status like that?
The status of your order No. Y21 has been changed to confirmed.
Because the modification reason..
or
The status of your order No. Y21 has been changed to canceled.
Because the modification reason..
If you want something like that you should probably change the language files to say that automatically. You can change the language file in the configuration menu > languages.
For example find
;Order statuses
CREATED="created"
PENDING="pending"
and ad something like that
;Order statuses
CREATED="created Because the modification reason.."
PENDING="pending Because the modification reason.."