Bug or they removed this feature?
Dual monitors - Windows 7 you could snap a window on either monitor to the outside and it would take up half a screen, you could then use the Windows Key + arrow direction keys to move that window to another monitor
Windows 10 - i can only snap on the Main monitor and using the Windows + arrow keys it will not move the window to the 2nd monitor..
I'm sure its a bug. Report it.