In prior versions of Feedback you could submit a request to merge two cases by drag & drop of one case onto the other on the CASES sidebar. This doesn’t seem to work any longer using Feedback 2015r1 (Cocoa). The drag & drop highlights as if something will happen, but when you release the mouse button, nothing does.
which cases ?
I think 29678, 30159 and 30328 could be merged.
I’ve at least marked them as related to each other if not outright duplicates
Is there a “please merge” request function any more in Feedback.app? Bug or intentional change?
I don’t honestly know
Greg’s the right guy to answer that as he works on it more than I do
Just click the Status link and you will get an option.
Oh, that’s pretty well hidden 
I assume “mark as duplicate” is the right action to take?
Any chance the old “drag & drop to merge” feature could be restored too?
We dont merge cases any more
There were issues around that
So they either get marked as related or marked as a duplicate
Probably not. As Norman said, we no longer actually merge cases, and this new mechanism combines several commands into a single function that we can update from the server without requiring a feedback update.