This seems crazy - while not every asset needs it (perhaps a basic 3d object can be judged by a preview) the majority do. It’s especially important for more complex things like plugins or blueprints where you can generally get a pretty good feel for whether they are going to work in your setup from the reviews and questions.
I can appreciate the logic behind consolidation of the multiple stores but this will be a big step backwards for UE users and a little surprising from Epic.
I wonder how Sketchfab users who are not commercial (for eg the many museum scan collections) will respond to this move - it looks like Fab is very much shop first, everything else second.