Materials on deleted children are applied to camera

Materials on deleted children are applied to the camera when inside of an actor blueprint. This issue does not appear to be a regression.

Versions Tested: Issue occurs in all versions Tested
4.16.3 - CL: 3561208
4.17.2 - CL: 3658906
4.18.1 - CL: 3754814

1. Create a new project ( No template or starter content needed)
2. Create a new blueprint > name it TestBP > Open TestBP
3. Add a camera component > add a sphere component as a child of the camera
4. Compile and save
5. Create a new material > open the material and add a color to the base color node
6. Apply the material to the sphere
7. Delete the sphere
   Result: The camera now has the material of the deleted sphere
   Expected Result: The camera does not change materials