Looking over the Unity Development Roadmap all signs of updates to UNet are now gone. The most recent blog post I could find is from 2017 and mentioned many changes were in the works. Was there an official update about the support/development changes that I might have missed?
Unet LLAPI is actively supported. Unet HLAPI isn’t getting any updates, and all signs point to it being replaced with a new system in the future. The best ongoing support for the HLAPI is undoubtedly HLAPI Community Edition.