The "it" they abandoned is the aircraft, they will continue to work on connectivity. They mention working with Airbus, they have a drone that has stayed aloft

The "it" they abandoned is the aircraft, they will continue to work on connectivity. They mention working with Airbus, they have a drone that has stayed aloft for 14 days. It seems like FB decided that they weren't making enough progress on building their own aircraft to justify not using someone else's technology for that piece of the overall project.