I’ve been a Redshift user for 2 years with C4D and I can most certainly confirm they are working on it and have been for a while. The devs have spoken on numerous occasions about progress and it’s much further along than people think. There’s just the issue of getting the IPR feedback better before they’re going to offer an Alpha preview.
Blender maybe changing quickly but so is Redshift and the transition to Redshift 3.0 has been much longer than anyone expected. Maxon acquired Redshift which also caused delays to development.
Personally I’m more interested in the Hybrid rendering modes of Prorender than Redshift as I think they have the potential to be as game changing as Eevee and the high quality mode offer similar image quality and speed to Redshift but for free.
While the Redshift devs have spoken about Metal for Mac only CUDA is supported on PC so AMD GPUs are still out of luck. They’ve spoken about Vulkan compute but it sounds like they’re only just beginning to look at researching it.