Commercial Flights Are Experiencing ‘Unthinkable’ GPS Attacks and Nobody Knows What to Do::New “spoofing” attacks resulting in total navigation failure have been occurring above the Middle East for months, which is “highly significant” for airline safety.
But that would also mean the timestamp to be off. Just resending them would also require extremely precise timing if you want to simulate a position that is not anywhere but just a bit off the last position. Making a GPS position jumping around half the world is (comparably) easy, pushing it off for a few kilometers is much, much harder.