I guess that means that everyone's EGPWS wouldn't be working in that area either, so no commercial carriers can be there (MEL item). Same with 406 GPS coded ELT's, all financial institutions would be shut down (they use the US Military GPS time stamp on all financial transactions), etc.
So probably a pretty isolated part of the world.
All GPS problems I've seen for the last ten years are related to GPS units themselves. Commercial operators, especially large ones like Bristow and CHC, are notorious for keeping absolute junk installed in their aircraft long after the "expired" date. Pilots are then forced to carry personal quality handhelds, like the Garmin 296. I've never seen those fail.
Interesting that the UK so thoroughly discounts the value of GPS for air navigation, yet feels obliged to be putting energy in figuring out how to jam it.
malabo