Repro steps:

1. Open project and scene “Scene”
2. Select object “Sphere (2)”
3. In Animation window notice clip “New Animation” (this is what works1 used to be called)
4. In Animator window select state “New Animation 0”
5. In Motion field observe link to “New Animation”
6. Click motion field entry and see how its actually animation clip “test”

NOTE: Trying to reproduce this in a new Animator Controller was unsuccessful

Reproducible in 5.6

Not reproducible in <= 5.5

Repro Project:
https://oc.unity3d.com/index.php/s/AO8n6bnO9i4lEpC