"Assertion failed: Internal: Possible leak. All textures should be removed from IdMap when destructed using RemoveTexture(TextureID texid)." when swapping from OpenGL to Metal, after deleting sprite and atlas

1. Set Unity to OpenGL 4.1 by disabling Metal Editor Support Experimental in Player Settings
2. Import any sprite, create a sprite atlas
3. Pack the sprite into the atlas
4. Delete the sprite and atlas
5. Open Player Settings and enable Metal Editor Support Experimental

Expected: No error
Observed: Assertion failed: Internal: Possible leak. All textures should be removed from IdMap when destructed using RemoveTexture(TextureID texid).

Occurring on: 2017.1.0b1 onwards until 2017.1.0b2 (current latest)
Not occurring: 2017.1.0a5, 2017.1.0a6