Note: As of version 1.2, TensorFlow no longer provides GPU support on Mac OS X.
> TensorFlow 1.1.0 will be the last time we release a binary with Mac GPU support. Going forward, we will stop testing on Mac GPU systems. We continue to welcome patches that maintain Mac GPU support, and we will try to keep the Mac GPU build working.
In other words, it still works (at least for now), and they'll accept patches to keep it working - they're just not going to explicitly test for it anymore.
And I'm sure you can imagine the reasons a large company wouldn't set up a Hackintosh. :) The writing is on the wall for being able to maintain a reliable test cluster, at least, for now, and broken tests are very very bad for being able to develop rapidly.