Dolby Vision is a much higher color gamut than HDR10, more like HDR10+. Would it be used in games or just for Blu-ray movies on XSX? Not sure. PS5 hasn't specified anything yet. Sony TV's support Dolby Vision and HDR10 but not HDR10+, so they either support HDR10 again for games or bother HDR10 and Dolby Vision.
It is very good for input lag, don't mix it with response time.
I really doubt it, you can wait for 2021 models if something will be shown, more than sure TV manufacturers heard the complains about the lack of smaller sizes HDMI 2.1.
I think that's input lag, response time is usually between 1-4ms as a standard or less. 11.6ms input lag for 4K@60Hz is extremely good, even for 4K monitors that struggle to hit that.
No worries, you're not missing much. But if someone didn't buy yet, seeking HDMI 2.1 is better for future proofing, but it's like 10% upgrade over 4K HDR
@60Hz.