In this case it was when they were opted into the location history, which is a continuing record of their movements that is shared only with Google within very specific conditions. In fact, the setting you've noted is actually one way that we've taken extra steps to give our users the information and the mechanism to signal that they don't in fact want their location tracked except when they're using an app. That one-time use only, when you're using an app only in this instance, is a way for us to provide additional control to the user.
On May 21st, 2020. See this statement in context.