pentimentosound
Meaning they've been "demoted"? and are now incorporated there?

No, the excluded dlls are in the PC path not in the dlls in the user VST path. This has nothing to do making old IKM plug-ins available.

Sorry Steve, but that is over my head! LOL  I will try rescanning again and a reset, too.
What would that mean to a "not so PC type" like me?

The excluded items are part of the Style Dials. They act like a wrapper, I believe.
All the best.

Hmm ... I tried IKM support a while ago on a similar point to do with their legacy products. Their reply was pretty much to tell me to pay to upgrade to ST3 and load all the legacy samples there. As I really only need these plugs to allow me to load older projects, I didn't fancy paying for a full ST3 licence. FWIW, these plugs were actually working satisfactorily until recently via BitBridge. My main concern about the sudden lack of these plugs is more to do with having broader concerns about the integrity of my recently patched-up installation.
 

Reset and rescan seems to have taken care of both my laptop and desktop.
Good luck to whoever's still not got it sorted!
 
Michael

Ensuring always to run as administrator, several resets and re-scans (with and without failed and all selected) and several system restarts later, the missing plugs suddenly reappeared. I have no idea what were the necessary steps, but they're back. Thanks for your help scook.