UK government have announced huge swathes of the country will be in Tier 3 covid restrictions. Hotels in those areas will have to close. People will be unable to travel from Tier 3 areas, so I doubt many people will be booking these prepaid 12% off rates. I say 12% because that is the reality. The cheapest existing rates are not the ones with 40% off!!
Plus the flash sale usually has bargain prices up until some time in March, this is until 10th of January then a lot of places are at their usual January prices. With no lounges available.