You still have to do all the work of building the geometries for the art assets, are you really saving that much on not having to color/texture those assets?
Maybe? One of the hacks of adding more assets without having to do much work is just recycling existing assets by assigning different color schemes/textures.
Come on, think bigger. If they're doing this for art styles you can bet your bottom dollar they'll be doing something using Google images. No longer having to actually create 3D meshes - just a Google image search, click a button and have the geometries automatically created for you. Then just add an automatic style.
Actually Google is just seeing the wealth of innovation in procedural generation and in computer creativity, knowing where this is going, and just want in on the action.
And since as a cloud gaming provider, they stand to make much more money than tool vendors, their incentive is much bigger.