I just googled the name of the game shop, seems like it only has 1 shop , perhaps theres not alot of buyer on that area, or the people are unaware of the news.
Furthermore...not alot of followers on twitter, so that explains it.
It is the only national physical gaming retailer the UK has.
It is hated upon for being expensive and just generally rubbish.
I think the issue is probably more that people aren't really thinking to look on Twitter for stock notifications in their local store they're trained to think that stock is only getting dumped online, as really that is where it has been dumped for the vast majority of the time.
Indeed on their website they had a restock last week and when I took a look the queue was over 2 hours long.
I mean you could literally buy it and sell it instantly for a profit to a shop we have here that buys and sells your unwanted junk so I don't think lack of demand would be an issue, it is lack of awareness.