Like many other posters, my company has been running into problems when trying to render Blender 2.8 scenes on headless, no GPU render machines. We are using AWS Thinkbox Deadline.
We are able to get Cycles to render scenes with just geometry successfully on the farm. But when we try to render Grease Pencil objects, we get the OpenGL 3.3 error dialog box, and the render fails.
We are aware of the MESA 3D/OpenGL32.dll workarounds that are out there, and we have successfully rendered a scene with Grease Pencil objects using it. But before deploying this method on 80+ of our farm machines and potentially opening ourselves up to issues further down the line, we are reaching out to the community to ask the question: Has anyone been able to successfully render Grease Pencil objects using Cycles on a headless render machine with no GPU?
I haven't found much info to back this up, but is Grease Pencil completely reliant on OpenGL? If so, it's pretty clear why we can't get it to work unless we use the modded drivers.