With an Inquisitor model disappearing from stock on the GW website, there is talk of models moving from Finecast to Plastic. This takes a look at that, and how small batch runs are being ran to maintain stock levels of some models.
Please remember that these are rumors.
via Stickmonkey on Faeit 212
GW is not producing finecast like before. Its moved to small batch runs, that they are only maintaining minimum stock on remaining models until they are replaced with plastic equivalents. And as stock runs out on some older models they are being discontinued even if no replacement is complete.
I think this may be what's happening to missing inquisitor models...the wide brim hat with plasma is also gone from what I see. Not that they will necessarily have a direct plastic replacement any time soon.