Andrew Price on Twitter: "@brian_m_tucker You can still use the emission shader in eevee, it just won't cast any light onto anything. The reason this *looks* like it's casting light is because
How do I make mesh lights (emission shader) work in EEVEE? - CG Cookie | Learn Blender, Online Tutorials and Feedback
light - Eevee emission reflections disappear when out of view - Blender Stack Exchange