No, we don't know those things.We know Disney is entering into the UHD BD format by Q3 2017. We know Guardians of the Galaxy Vol. 2 is coming, per James Gunn (Please let it be a Dolby Vision encoded disk). So, if they happen to announce anything else even earlier, it will be a nice surprise. Disney had said last year they were watching how the format was doing, and they had no plans to release UHD Blu-ray disks in 2006, or 2007. So, they must have finally decided the format is successful enough. I really hope Disney puts most of their titles out in Dolby Vision, it's the premium format we deserve.
If you have any proof that Disney will start releasing on UHD by Q3 2017, please provide it.
And unfortunately, James Gunn's Twitter comment is vague. Scott Derrickson basically said the same thing about Doctor Strange. But he was a little more clear saying that he graded UHD master that will eventually come out. No time frame. And as we all know, Doctor Strange is out digitally now, and on disc in 2 weeks with no 4k version.
I can cite many more examples of Disney having created home UHD HDR grades for their movies, yet are sitting on them. They will release them only when they are ready. And they have not yet announced when that will be.