I just assumed it was because it was driven by the North American region. They care about IMSA more than WEC. Obviously they care about Le Mans, WEC is just a necessary evil for them?
And as it is NA driven the way it is starting and being built up starts there for ease too.
So no great plan, more just how it is.
Could be wrong. As it is just an assumption. We tend to over think these things and this assumption certainly isn’t over thought!