Last week, it was revealed that Fortnite would become free to play streamed for everyone with Xbox Cloud Gaming, even including people using Iphones, where Apple has banned the game. Normally you would need a Game Pass Ultimate subscription to get the cloud gaming feature, but clearly Fortnite was an exception.
...or perhaps rather the beginning of something new? If the Windows Central editor Jez Corden is to be believed, Halo Infinite's multiplayer (which is currently free-to-play and available on Xbox Cloud Gaming, but a Game Pass Ultimate subscription is needed for the latter) is about to become playable the same way as Fortnite.
Basically, you will be able to play it streamed on whatever unit you have for gaming with Xbox Series X level graphics for free. No paid subscriptions of any kind needed. If this would actually happen, we assume more games will follow suit, which is a clever way to make people enjoy free-to-play titles in the Xbox eco-system without even having a console or subscribing to Game Pass.
Thanks Idle Sloth