The Argyle mine stopped digging up pink diamonds, I am pretty sure it's to maintain value of the stocks in circulation and held by the company.
They were very keen to find a lode source kimberlite pipe and get more pink diamonds but sadly .. no show (as of the last time I looked at the Tech. Reports on regional exploration).
There was absolutely a financial element on the decision to shutter and rehab the mine site .. but it was driven more by diminishing returns at that deposit than by market starving.
They don't seem to have any plans to reopen as they're supposedly going into full rehab mode (all equipment gone, return to nature):
https://minedocs.com/26/Discovery-and-Mining-of-the-Argyle-D... is old but fascinating and had great photos and maps.
