Yeah, I'm hoping it requires use of the xbox app which is logged into my years old xbox account, or the same log in stuff that GFWL used.
I find MS Support quite good,if you have problems they deffo will help you.
They canceled my standard FH3 preorder (dont even know why i ordered standard in first place lol) and changed to Ultimate in a minute.
Quite sure they will help you,but maybe you need to chat wit them before friday?