I don't know if you get the 1000 Fortnite V-bucks with that link. Maybe.
These links mention getting it.
https://www.xbox.com/en-US/promotions/gold-offer
https://www.xbox.com/en-GB/promotions/gold-offer
Valid only for new subscribers or users who canceled their subscription before 10/1/2018. Limit: 1 offer per account; credit card required. Only valid through link in this offer, in all Xbox Game Pass markets excluding Quebec. After first month, subscription continues to be charged at the then-current regular monthly price (subject to change), unless cancelled. Plus applicable taxes. Game catalog varies over time. Not valid for existing subscribers . After promotional period, subscription continues to be charged at the then-current regular monthly price (subject to change), unless cancelled. Plus applicable taxes. Limit: 1 offer per account. Only valid through link in this offer, in all Xbox Live markets excluding Quebec. Credit card required.