But wouldn't that apply to Xbox One, One X, and possibly XB360 direct sales as well? Yes, direct sales aren't being included, but that would include Sony and Nintendo direct sales as well (that aren't being provided). Unless, you believe Microsoft direct sales are somehow outpacing box store sales tremendously in the UK?
Not really because of two main things..
1. Microsoft had put out official numbers for Xbox One at time of launch and didn't stop providing them until October 2015. So nearly the entire 104 weeks were probably official numbers for Xbox One.
2. Direct sales weren't as large then as they are now.
For around 4-5 months at the end of 2021 and beginning of 2022 you could only really get Series X direct from MS in the US. I don't know if the situation was the same for the UK. Nor do I know how many they have sold directly.