The partnership was announced on February 25th.
As someone who's current phone is the HTC One M8, I think dual cameras are more of a marketing gimmick than an actual useful feature. They're fun for a bit, but the ecstasy soon wears off. One really good sensor is better than two mediocre ones.
I had high hopes for the partnership, but this is a bit disappointing
Relevant old thread.
https://forum.teksyndicate.com/t/huawei-and-leica-announce-partnership/97564
There's an unboxing of the device on youtube now: https://www.youtube.com/watch?v=5FID5kWGSyg
In it, the unboxer explains that one of the cameras is monochrome and more sensitive light, allowing the user to take "high contrast B&W pictures" as well as color pictures with variable focus (you can change focus after the fact). In the video, latter looked pretty good to me.
high contrast or high dynamic range?
As for the dual camera "gimmick" I have an LG G5 and I love the two cameras. If I want to get a very wide angle of a landscape or cityscape I can do that quickly without having to take out a DSLR which is nice when I go cycling. I would love to see some of the images that get produced by this phone though.
If the P9 is as good as mine P8 wow great door stopper with dual lens.