As Apple's own GPUs do not run full OpenGL, does this in turn mean they didn't only create a x86 to ARM translation layer but also a full OpenGL implementation

As Apple's own GPUs do not run full OpenGL, does this in turn mean they didn't only create a x86 to ARM translation layer but also a full OpenGL implementation running on top of Metal? Similar to other projects implementing OpenGL on top of Vulkan? Or did they actually invest the time to implement OpenGL directly in their graphics drivers? That seems a bit weird considering OpenGL has been deprecated in macOS already. I would have expected a full removal once the first ARM Macs ship.