The harsh split certainly wasn't like that for the original game, nor many other games. I think the reality is that the late announcement meant many had already decided to buy digital, or weren't aware of the retail version. And availability was likely lower as many stores will have already made stocking decisions earlier on before XBO version was announced. Just my hunch.
I just wish the charts included digital purchases. It would make things so much more interesting - and better reflect reality. I remember when this was put together recently for the UK and showed Cities Skylines at the top spot, and Ori in the Top 10. Tells us so much more about the market than just retail boxes shifted through retail stores.