Unity is being required to ditch Enlighten due to Geomerics shutting it down. While Unity will continue to support it through 2020 LTS, they are working diligently with a new group to produce a new lighting product by 2021.
"Our Lighting team has been focused on making a robust solution to replace Enlighten baking over the last years as well as provide great alternatives for the fast workflow possible with real-time Enlighten pathway through improved baking. The CPU Progressive Lightmapper is production-ready. Our GPU-based Progressive Lightmapper is used widely now with a great set of features and is targeted to be production-ready in the 2020.1 release. We’re continuing to add improvements, focusing on highly-iterative workflows, with every release. For example, in Unity 2019.1, we’ve added NVIDIA® OptiX™-based AI denoising, which gives you perceptually noise-free lightmaps up to 10x faster than before and many other features targeted for easier, more intuitive workflows and faster iteration for artists," Unity said.
More on this development can be read here.