Animation Orientation does not Auto-Convert to UE4 Coordinates when Reimporting

Animation orientation does not auto-convert to UE4 coordinates when reimporting the same way it does when importing the same animation as a new import. In other words, a run animation generated from a 3D Program where it was created "Y-up" will convert to "Z-up" when imported as a new animation.

If this same animation exists Z-up in UE4 and you select reimport and choose the "Y-up" FBX, the animation will play face up or face down (it will not covert Y-up to Z-up as it does as a fresh import)

1. Open a Third Person Blueprint Project
2. Export the "ThirdPersonRun" animation
3. Import "ThirdPersonRun" animation into a Maya file with Y set as Up in the settings.
4. With Y up, export the animation as an FBX
5. In UE4, import the animation using the existing Mannequin Skeleton (Give it an original name to not affect the second part of test; ie "ThirdPersonRun2")
6. NOTE: The coordinates are converted to Z-Up
7. Now select the original "ThirdPersonRun" animation and select "reimport"
8. Choose the FBX you exported from the Maya "Y-Up" file
RESULT: The newly imported animation will be lying face up (or down) horizontally because the orientation axis was not converted as it was for a new import.
EXPECTED: The orientation of the reimported animation to be automatically converted as it is for a newly imported animation.