Buy Battlefront 2 on Xbox and play on PC (Microsoft Store), is that possible?
If it's play anywhere. It's actually there.
Windows 10 is also required
Since the game is not in the Microsoft Store, no. (At least not on the PC.)
Star Wars Battlefront II is not a Play Anywhere title. If you buy the game on Xbox One, you still don't have it for PC. Here is the official Xbox.com site with a list: