Not that I’m aware off, it helps you manage them at once and separate them as a group for easier compositing or make these lights exclusively affect one item if you set it up like that. Once you use these light groups, you do need to be aware that it will impact your scene the way you set up these groups. But that doesn’t happen by just assigning the lights to a group. You have to tell Blender what to do with this group before it has impact.
