It should be able to select which activities will sync from 3rd party apps. For example if one is riding on Zwift, and still uses a Garmin device to record the activity for other than Strava reasons, after the ride, both Zwift and Garmin Connect are currently synching and one has to ALWAYS delete Garmin activity manually. I bet that not all want to sync all activities from connected apps. In this case i'd turn off Garmin Connect sync for Indoor Cycling.
Thank you