Very strange I must say. I certainly understand brewery-only test batches, homebrews, brewery-internal only releases etc being unrateable, but this?
Also, how is that any different from:
http://www.ratebeer.com/beer/the-bruery-black-tuesday-reserve/372946/? In fact, the Mikkeller one is MUCH more "commercially available" than The Bruery Black Tuesday Reserve. That’s a Hoarders-only release. Not only is that gated behind premium membership, but I can’t even PAY to access it, since Hoarders is an invitation-only membership. Same goes with the other Bruery Hoarders exclusive beers. Or from other breweries which have invitation-only clubs.
I can see that Bruery Reserve and Preservation only releases might be rateable since these societies are available to everyone (well, as long as they are not sold out that is). But saying that SAS-only beers are not eligible while allowing society-only beers are inconsistent to a fault.
To my mind, the only unraetable beers should be homebrews, brewery test batches and brewery-internal only beers. The rest should be allowed.
Or, if you want to be strict, also limit beer club limited beers. But the better way would be to add a tag to these beers, in the same vein as Retired ones.