There are dozens of ignored feature requests that are years old in Adobe's forums.
Metal was released almost 2 years ago and still no signs of coming to Photoshop or Illustrator.
But here we have support for a gimmick that only a very small percentage of mac users will be able to use.
Adobe has its priorities straight.
What could they possibly get out of moving to Metal? Their OpenGL drawing can be a little wacky at times. OpenCL seems to work well enough for computation. It's also a cross platform application. Otherwise it might make more sense to just whatever direction Apple goes.