Operating system: Windows-10-10.0.17763 64 Bits
Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 391.01
Broken: version: 2.82 (sub 1), branch: master, commit date: 2019-10-28 21:19, hash: rB2dab4393b08e
Short description of error
Blender doesn't keep child-parent properties with duplifaces (and other instances too i imagine) with "Keep hierarchy" checkmark enabled in "Make instances real" properties
Exact steps for others to reproduce the error
In the sample file, ctrl+a => make instances real with "Keep hierarchy" checkmark enabled, but parental relationships are not kept.