OnCollisionExit2D no longer gives contact information

Up to 5.5.0f3, Unity gives us contact information in Collision2D parameter of OnCollisionExit2D, however, it doesn't in Unity 5.6.1f1.

I don't know whether it's a bug or an intended behavior. There's a test project to reproduce the problem.

Reproduce steps:

1. Open the Attachment Project in 5.6.1f1

2. Open the "Test" scene

3. Run

4. After falling the cube on the ground, Console prints "collision.contacts.Length: 0" (w$$anonymous$$le it should be 1 not 0)

If you follow the same steps as above in 5.5.0f3 and prior versions the console prints "collision.contacts.Length: 1" w$$anonymous$$ch is expected.