No, the new Macbook Pro does not have a BT.2020 screen. It's P3 colorspace. Currently only a few RGB laser projectors can reproduce almost 100% BT.2020. LCD and OLED displays stay at 80% coverage.

No they don't have Rec.2020 capable screens. There won't be any in the near future.

a6300 already does full sensor readout from 6K to 4K, a6500 does not change that, but with new LSI front-end, the readout speed will likely be improved which results in less rolling shutter compared to a6300 which is mind-numbing 32ms.

CMOS sensors on modern digital cameras always have UV and IR filter bonded on the surface, they also act as a protective layer as well. Different manufacturers may have different spectral response on these filters. Using this SLR Magic Enhancer may yield different results (good or bad or none) on different cameras, since no camera captures the full spectrum natural light as demonstrated in the first picture of the spectrum curve.

1. You need HDR monitor to grade HDR content (Sony BVM-X300 for example).
2. SDR version can be derived from HDR version using manual trim pass and "Content Mapping Unit".
3. Several online streaming platforms such as Netflix, Vudu already support HDR.
4. HDR is mostly encoded in H.265 codec (in 4K HDR Bluray Disc), it must be minimum 10bit. There's a moderate increase in file size (4K HDR Bluray Disc is mostly 66GB currently)

Thanks, but you skipped the 4K prototype monitor right next to the DM170...