Pokemon Go has added Shadow Zapdos as Giovanni's latest Pokemon. Team Rocket's plans for Pokemon Go have continued into the month of December, resulting in a new Special Research quest and a new Shadow Pokemon for players to face. The "A Challenging Development" Special Research quest was added to Pokemon Go earlier today, which culminates in a battle against Giovanni and his new Shadow Zapdos. Completing either this Special Research quest or the "Looming in the Shadows" Special Research Quest will earn players an encounter with Shadow Zapdos if they can defeat Giovanni.
The switchover comes with a few noticeable changes to Pokemon Go. First and foremost, players can no longer capture a Shadow Articuno, even if they did not complete the November "Looming in the Shadows" quest. Players who haven't completed "Looming in the Shadows" can choose between capturing Shadow Zapdos twice (once for Looming in the Shadows, and once for A Challenging Development) or they can hold off on completing "A Challenging Development" until January for the chance at a second Shadow Moltres.
While players are still working on completing "A Challenging Development," it appears that the steps are identical to "Looming in the Shadows," which means that players should be prepared to spend a lot of Stardust to purify their Pokemon. If Giovanni's other Pokemon hasn't changed from last month, players should still be able to beat Giovanni with the team they used last month, as Zapdos can still be defeated by a strong Rock-type Pokemon. All of the other Team Rocket Admins also use the same Pokemon they used last month.
The only big question remaining is whether Pokemon Go will re-use Shadow Articuno in February or if they'll switch to a new set of Legendary Pokemon. From what we understand, the Team Rocket events will continue on a monthly basis for the foreseeable future, so we'll have to see if Pokemon Go will make any big changes to keep the events from becoming repetitive.