There is a field "Product Lifecycle" that allows you to mark a module as discontinued. Use that. You can even filter on it. It was created for that exact purpose.

Problem is that most modules don't have that flag attached and are listed under the Property unassigned label.
We should make some kind of community data sanitation event to complete the data at one point...

the edits spurred the rant about had this field set already - ie Doepfer stuff. A quick search yields that 24 or 37 with the word discontinued in it, have this field set.

I agree it's a community effort. That's the point, really. There is quite a bit of effort to be had without people added to the the pile. (duplicate entries, incomplete entries, person modules not marked as private, etc).

I personally updated the field on 250+ modules. There are some that are manufacturer locked but generally the major manufacturer stuff is marked properly.

this is the 3rd fucking time I've had to change this on the Doepfer a-126. Can an admin step in and tell these motherfuckers to stop reverting the name update to remove "(discontinued)" and pay attention to the goddamn field that is there for that exact purpose!!!!!!!!!!!!!!!!!!!!!!!!!

I feel your pain. At least the modules with discontinued in the title are correctly tagged as discontinued.
To prevent the reverts in the future I have put a red alert label to discontinued modules in the module browser. Maybe that will help.