I wouldn't consider the two examples you posted to be "necro-bumping". To me, it's a previous post that is at least 1-2 years old.
Fair enough. They were replies to old topics which hadn't seen any activity for months.
Since this was repeated on multiple threads in the legal section, I thought they would fall under this
.... you read the subject line, maybe the op, pound out a quick response, move onto the next thread, rinse and repeat