We’ve gotten details from TheSilphRoad that Raid Eggs have returned to GO. At first, Raid Eggs would appear two hours before a Raid would begin, coaxing players into all gathering at one Raid location. However, this feature was dropped after legendary Pokémon were implemented into the game. The current Raid Eggs will appear two hours before the actual Raid. The Raid battle time is also set to one hour now. It’s unknown at the time whether the Raid Eggs are permanently planned to stay in the game.
Edited by ddrox