Niantic has announced in a blog post (link) that Moltres and Zapdos would be coming to Pokemon Go very soon. Players who have not captured Articuno should also hasten up as the Team Mystic icon will not be a permanent addition in the wild.
Here are the following time periods where the Legendary Birds will appear:
- Articuno (Team Mystic) released on Saturday, July 22 and available through Monday, July 31.
- Moltres (Team Valor) to be released on Monday, July 31 and available through Monday, August 7.
- Zapdos (Team Instinct) to be released on Monday, August 7 and available through Monday, August 14.
Each Legendary Bird will only appear for one week so act fast!