I am not Garmin, so not sure. But I would think it is only the contacts that you put in the new Contacts menu in Garmin Connect Mobile. These contacts are certainly needed for the feature to work so it makes sense. They could be clearer about what they do.
I don't have the option, on my iPhone with 12.2 to add garmin connect to access my contacts so, I can't even get to the place that your screen shot shows. This update/ or, lack of being able to use livetrack is very troublesome. I used to rely on it as a safety net for my long rides...