There is also the 4K Spears & Munsil disc available for further calibration and testing of TV-Led vs Player-Led by the likes of RESET, Vincent from HDTVTest and others in the industry. To put it most simply, just remember that Dolby Vision requires a special SDK/engine to be used and not unlike audio being able to "pass-through" to an AVR, the metadata for Dolby Vision also can "pass-through" and that's essentially what TV-Led is describing. It's technically possible some lower-end TV would not even properly license or play DV metadata but that's why folks like RESET test on multiple displays and Dolby obviously has a relationship with the likes of Sony and LG to ensure their top-end models properly implement Dolby Vision in TV-Led mode, at least with their own Blu-ray players and possibly major streaming apps.
Hopefully that makes sense, there are times to be skeptical, but this is not really one of them, as RESET, quietvoid (and Vince from HDTVTest etc.) don't work for Dolby and have put all of the labour and research required to understand and test Dolby Vision as objectively as possible, so you don't have to.