That was a feature where you could attach an analog receiver to their Goggles v2. They have since removed it in newer Goggle versions. Their system is basically a walled garden now.

I think DJI might be referring to the recently introduced “race mode”, which reduces bandwidth of their transmitter and allows other pilots (with analog systems) to fly nearby. In regular mode DJI video systems tend to interfere with analog transmissions.

I haven’t heard of any official way to get analog video from a DJI air unit.