Bob H "The drone could try to return to base but it would lack GPS..."
The antenna is clearly wifi band, 2.4 GHz. I own several, so I recognize the $10 eBay item. The article states that it blocks the command and control link, in the wifi band.
GPS is not in the same band, but is about 1.6 GHz. Would require a different antenna (Log Periodic) to cover both bands. Plus, duh, they're not going to suggest jamming GPS next to an airport.
.: The wayward and/or illegal drone will retain GPS.