UE 4.12 - VR Loading Movie?

[SpeedySoul]

In the UE4.12 Preview's release note
https://forums.unrealengine.com/show...e-4-12-Preview

it said

VR Updates:
...
VR Loading Movies - You can now have framerate-independent loading movie support.
...

But in the official UE 4.12 release note it wasn't mentioned at all.

What is VR Loading Movies about? Is there any documentation or thread discussing about it?