We had a call for content of studio lights, but all the env maps used were removed because the studio lights got reverted a OpenGL dot shader like before, with a extra light source, smoothness and ambient properties.
but the defaut ones are just unusable for actual modeling tasks, they are too low contrast and actually hide mesh features, I see many people going to use matcaps because of that, I think we need new default presets for studio lights, ones that can actually be used.