Please remember that there has been no official announcements of changes to GW finecast resin. So these are still rumors.
via a reader here on Faeit 212
So I dont think I saw an official notification from GW that finecast was gone now but I received my 10 legion of the damned guys today and they are a dark grey plastic/resin much like the FW mini's.
See pix attached, I saw a warp spider in this material too today and its really good stuff, not a single fault in any of the 10 I ordered.
I actually found a few old finecast bits and these newer models are a slightly lighter shade of grey, and I can only exainplain the colour and lack of faults on it being a new material.
Though I did start second guessing myself but it seems to be harder to drill and than the older stuff.
It just feels more like the harder FW resins. The store manager seemed very interested in how good these were and I was like this does now look like finecast.
Who know either way I have never seen so many faultless models in one place ever :)