I use PC in high contrast mode and it seems to work pretty good with windows 10. The applications are not so great, I have to alt-shift+PrtScr every time I want to print something like invoices at work, and some web page graphics just show as black squares. Looking forward to a Windows build that has a dark mode builtin that hopefully will work better with other applications.
This could actually be a good idea then again I think we have been able to do this with Windows for a very long time but the twist I guess would be that Windows will now switch at certain times of the day to the dark mode for you where as before you had to switch it yourself. I use Youtube in dark theme mode 100% of the time because it is just a lot easier on my tired eyes. So I could see myself setting this up for evening use after work maybe it would save my eyes from the 60" TV screen I use from across the room in the evening.
The dark theme for file explorer is not new with this build, it has even already made it into the last update build I got in the slow ring. I usually think of Tomshardware as much more knowledgeable than this.