Have you even read the info that someone linked here? It says that it works exactly like that.
"the device?s owner has been identified as ?feeling unwell?, and we have a list of devices that have been in ?risky contact? with that same device. We use our notification system to get those devices to notify their users and ask them to self-isolate for a couple of days[4]. Then one of four things could happen, depending on health policy:
You get a clinical test and test negative. In this case, your contacts are told that it was a false notification. You get a clinical test and test positive. In this case, your contacts are asked to isolate for 14 days, and get them into the clinical testing path. You don?t get a test, but too few of your contacts report symptoms to statistically suggest that you were probably infectious. Your contacts are told they don?t need to continue to isolate. You don?t get a test, but enough of your contacts report symptoms to statistically suggest that you were probably infectious. Your contacts are told they need to continue to isolate."