As an instructor, I have accidently deleted student discussion posts many times in the past. Several of my students have done the same.
There is no warning/confirm messsage and there is no way to recover a deleted discussion post in the event one is accidently removed. The Canvas support desk cannot recover them either; they can only recover entire discussion topics, not individual postings.
I would like to see both a warning message with a confirm delete message and a recovery option for either (or both) Students and Instructors.