I don't understand.. just looked and can't see any difference. What does the flag look like and what difference does it make?
I could still see your rides, if they were private as you say I'd have got a message saying this activity does not exist.
A flag puts a red banner across your activity and says this activity has been flagged and removes your times from any leader board.
Rides usually get flagged by the holders of KOM's that have been taken, sometimes people keep the Strava running whilst travelling in a car, so correctly if the user doesn't correct it they can be flagged. Clearly yours have been flagged as a direct result of being posted in this thread.
I once had a ride auto flag when uploaded to Strava because it was that fast.