Cara, então, olha só a notícia do anúncio dessa novidade:
https://majornelson.com/2018/01/23/...-include-new-releases-from-microsoft-studios/
"Moving forward, we plan to release all
new Xbox One exclusive games from Microsoft Studios into
Xbox Game Pass on the same date as their global release. This means that when
Sea of Thieves launches on March 20, it will be included in
Xbox Game Pass to all members.
This plan to bring new games timed with their global release into
Xbox Game Pass not only includes announced titles like Sea of Thieves,
State of Decay 2, and
Crackdown 3 but future unannounced games from Microsoft Studios
including new iterations of our biggest
Xbox One exclusive franchises such as
Halo,
Forza and
Gears of War,
on the same day they launch."
O anúncio foi esse, por isso que to falando que eles não deram garantias sobre os antigos exclusivos. Pode ser que eles adicionem, mas não há garantias nem prazo. Mas pode ser também que perdi alguma informação aí rs.