Winefront reviewed the 2016 Signature today by coincidence and gave it 93+. Possibly gives more credence to the fact it is the wine in question if it's also being sent out to reviewers ready for the market.
Personally, I think you're better off buying the 2015 from First Choice which is guaranteed to be the actual wine and fully labelled for ~$38 with the current 30% shopback promo. I agree with someone else who mentioned that it's likely to be Signature but possibly slightly different (and inferior) for the export market. If I did buy the GWD version, I would be happy to drink the unlabeled version at home by myself but I would feel too embarrassed to take it to a dinner or someone's house so it makes sense that it's dirt cheap as it needs to be.