yes it does have workspaces, 9 of them that aren't just moving around windows but windows's own Virtual Desktop, but no the state isn't stored through reboots, though that is one of the goals.
I have dozen named workspaces on i3. Limiting them or not providing the ability to (re)name them or create them on the fly makes the whole experience of virtual desktops pretty lame.
The biggest issue on W10 is that there's no way to even more windows from one workspace to another without several clicks, unlike most Linux implementations that have hot keys or dragging the icon around.
Where does that limit of 9 comes from?
Doesn't Windows 10 accept more that 9 desktops?
I have tried the shortcut Ctrl+Win+D and could create more than 9 desktops on my Win10 install.