I was serious, I do log in and office lol I send them info on that too, even if I am not supposed to have it
There is a problem with 9879 where all keyboard lights are turned off (caps lock, num lock, scroll lock). Those functions and keys are working properly but there is no signalization if they are turned on or off.
I believe that one, in particular, is just referring to the newly added OneDrive folder within your user profile. So not necessarily sending directly to the OneDrive program itself. Although I am sure whatever is within that folder would get synced at some point.
Build 9879 has a better performant AHCI driver I don't know, if this has already been mentioned here: Win10 Build 9879 contains a brandnew generic AHCI driver named STORAHCI.SYS. It has the version 6.4.9879.0 and is dated 11/04/2014. According to my benchmark tests this new AHCI driver is much better performant than the storahci.sys versions, which have been in Win8/81 and the previous Win10 Builds.
AHCI used to be problem in some systems when doing Windows setup. It often times request for the controller driver to be installed for the HDD to be visible or for installation to progress from that point. Having said that, I don't know how this new system file addresses that issue. However, my system is on RIAD 0 using SSD and the performance is better than AHCI (even when using multiple HDD).