A few months ago, Pokemon GO developer Niantic changed up the way it was doing Field Research Breakthroughs. Instead of a guaranteed legendary Pokemon as the reward for a whole month, it shifted toward a pool of legendary Pokemon rewards for a similar, if not extended, period. Now, that we're moving toward the end of the March and April Field Research Breakthrough rewards, the developer has revealed what Pokemon players can expect next.
Prior to May 1, this was an extensive list composed of Ho-Oh, Lugia, Entei, Suicune, Raikou, Regice, Regirock, and Registeel. For the coming months, however, the list has been chopped down considerably, leaving Ho-Oh, Lugia, and newcomers Latias and Latios as the Pokemon GO Field Research Breakthrough rewards for May and June.
This rotation will take place at 1 PM PDT on May 1 and run through 1 PM PDT on July 1, with this drastic shift seeming like a double-edged sword. On the one hand, this means that Pokemon GO players who haven't got any of the four aforementioned legendaries have higher chances of getting one over the next two month. On the other hand, Ho-Oh and Lugia have been in the pool for some time now, and both Latias and Latios have had extensive raid events.
This would suggest that Pokemon GO players who have been diligent in completing their Field Research and partaking in various events will not have much incentive to complete Field Research for the next two months. That is, of course, unless there is an event underway, like the forthcoming Torchic Community Day.
Regardless, there will likely be even more events over the next two months to get players from all walks of life involved, so this may prove to be a non-issue for many Pokemon GO players. We do know every single Pokemon GO Summer Community Day date, as Niantic revealed this not too long ago, meaning that it's like to be a packed summer for the mobile ARG.
Pokemon GO is out now for Android and iOS devices.
Source: Pokemon GO Hub