I'm not commenting on the individual case here and 32 red, but it wouldn't surprise me if the average income level to postcode information wasn't used by some gambling firms in their marketing/promotional decisions. Say they have a
£100,000 monthly budget to attract more turnover/business it could be argued irresponsible to use it to target players from poor areas, and just on a pure business decision level they also have less available income to lose/gamble.
I think one of the concerns many had with the SOW process was that casinos would then know exactly how much 'disposable income' you had each month, so if that fear was believable why not also this postcode data possibly being a factor? [Not the deciding factor though]
This site does a similar thing in a general way