What's the status of explicit Mip Level Streaming? (Texture2D.LoadMipLevel)

Hi,

I noticed in the following post by @Joachim_Ante that there are plans for explicit mip level streaming via a new Texture2D.LoadMipLevel method in Unity 5.x: Unity 5 Level Streaming

What's the status of this? Is it still coming and if so is there any indication of which Unity release it will show up in? I don't see any specific mentions of it in the Unity roadmap (unless it's related to Graphics: Async Texture Upload in 5.3?).

Cheers,

Andrew