I vote for a new Vulkan forum, as I have no more interest in OpenGL but a strong one in Vulkan.
We traditionally create new forums reactively, not proactively. That is, we'll create a separate Vulkan forum if there's so much traffic and discussion that it's detrimental to the OpenGL forum. For the time being, this forum will be OpenGL and Vulkan. Should see about getting the name and description updated.