This is one of those things that feels viscerally weird to me (Who the hell is playing Fortnite for the “Universe”) but then I remember Mojang and Microsoft were able to do basically the same thing (to incredibly profitable results) with… Minecraft of all things.
It’s kind of a weird state of things. In the past you had various Universes (Lord of the Rings, Star Wars, etc) that got adapted into games and such. Now you have games that get adapted into Universes. Different culture in a way.