JOGL doesn't support Vulkan yet and it's not something trivial to implement as Vulkan is a lot lower level than OpenGL. Moreover, using Vulkan would require a completely different renderer in each middle and high level API based on JOGL.
I assume that free OpenGL drivers will be available when Apple drops OpenGL completely but it will be a bit cumbersome because it will be up to the end users to install them and it's typically the kind of things most OS X users aren't accustomed to :s