It’s a direct follow up to this problem: Time.deltaTime Not Constant: VSync CameraFollow and Jitter
Now when you run the player on DX11, Time.deltaTime will tell you the actual amount of time a frame has been on the screen, rather than the time difference between two points in our C++ codebase that executes on the CPU when VSync is enabled. This makes Time.deltaTime to not fluctuate unless your frame rate is missing vblanks.
The fixes for this for other platforms/graphics APIs are coming too. I just can’t tell you when :).