I don't think they do. Amazon will supply all around Europe and there may be a difference in the manufacturers terms for rebates, gifts warranties in each country. If they advertised that the item qualified for rebates etc then you would have a pointIn which case don't Amazon have a duty of care/obligation to state on the item purchase page that for UK buyers is non UK stock i.e. a grey import?
With regard to cashback & gifts I think it is incumbent on the purchaser to check out the terms on the manufacturers website before buying