The Cycles integration is going strong and doing well.
Eevee is indeed completely different from Cycles, but in theory it should be possible to integrate. That said, the problem is the license of the source code. Eevee is created under GPL, meaning that we can not legally integrate it to Rhino, not even as a separate plug-in. You can find this information in the source code here: https://developer.blender.org/diffusion/B/browse/blender2.8/source/blender/draw/engines/eevee/
/Nathan