Re-opening closed threads

[hot4teacher]

I was wondering if there's a way for the threads to only be marked as unread if there is actually a new file/attachment.
Recently, a lot of people are posting simple thank-posts which are re-opening threads that have been closed for up to several years - rather than just using the thankpost button (or using it at all) - and I am assuming that this was probably one of the reasons that the thankpost bar was implemented.

It's not urgent - just a bit unnecessary.