During the Hoenn Pokémon Eggs event in late January there was temporary change in Pokémon species hatchable from eggs. Only previously added Hoenn-region Pokémon were hatching from eggs between January 23rd and February 1st, 2018. After this time the all hatchlings were the same as prior the event.
During the Water Festival 2018, there was very high chance to get 2-km Eggs with following Water-type Pokémon hatching from them. After the event ends, eggs hatchlings will be the same as prior the event.