It's very unlikely it will be used in video games. Video games pretty much exclusively use texture mapped polygon meshes as data structure. They easy to render, they plays well with object animations, they allow for dynamic lights, and there exists a lot of mature software to create and edit this data. 3D Gaussian splats also render quite fast, but they are bad for animations, they don't allow for dynamic lights (as far as I can tell), and there are basically no tools to create and edit models, except from photogrammetry.