Do you understand how the new light system works? Yes, level 40 is the max experience level, but after that is the light level. In the stream when the community guest died it showed what killed her and that the recommended light level for that enemy being 240 (it goes much higher than this im pretty sure, up to 400 at least is my guess). The higher your light level is the more damage you do and the less damage you take. Bungie has said this a few times already.
Its a whole new algorithm for calculating both attack values against an enemy and the damage you take from an enemy. Furthermore, its impossible to say exactly how it will work as it is a whole new system compared to what we know and we wont know until its released.
English
-
Bungie never stated they were changing how levels worked, only light. In D14, level 17 fighting level 18s is like a level 27 fighting level 28s. The same 33% modifier applied, and light meant nothing aside from being a higher level. So you can see my confusion and concern, especially considering it took a third party reviewer to provide the answer to how light and levels will work, and it took him like 5 seconds. Bungie never mentioned how the new system would work, only that there would be one, so I dont think it's unreasonable to be concerned about how levels would play into light. Check my updated OP, it has all the info courtesy of Datto's video