Unless they can scan multiple billions of billions of star systems in full 3D (up, down etc) there will be very little chances they will know were we'll be located exactly just with this flag. Also keeping pluto on the flag as a planet is a good assurance to mess up with their google cosmo-map system, just in case...
And it will be harder if Earth doesn't have any flag right? I think the flag is not only tell something out in space where Earth is, but it will be the identity of our planet. I guess NASA will make the flag for other planets in our solar system.
