Interesting. I believe you are right, I just tested and the emissive light did not light my character.
The reason I decided to try fully-emissive lighting was that my walls eventually should be destructible, and having light in the texture I thought would allow for simpler destruction mechanics, simply destroy the mesh and the light also vanishes. I will find a way to work around that, it should not be too difficult to remove lights when the asset is destroyed.