This pattern is entirely predictable
"See how Windows 7 peaks for five days, then dips? And see how Windows 10 and Windows 8.x surge at the same time Windows 7 dips? Line up the days from the data and you'll quickly see that Windows 7 thrives during the working week and other versions of Windows do better on weekends"
It has always been the case that enterprise adopts a new Windows iteration at a slower pace than the domestic retail market. I would be utterly astonished if that were not the case this time as well - it is not even yet six months since launch.
However, given that the current Enterprise version of Windows 10 enables both blocking of updates and blocking any "slurping" this iteration does not present issues for the business sector in the way that the Home and Pro editions do for private customers. That means of course that if there is no significant uptick within enterprise over the next year or so then MS would have good reason to be worried.