Double EXP September 24 question

The September 24 Spotlight Hour (Rattata) gives double EXP for evolving pokemon.

Does this apply to only evolving Rattata, or is this a good time to stock up on Pidgeys to burn all my 550 candy for a mass evolve with a Lucky Egg?

https://www.eurogamer.net/pokemon-go-spotlight-hour-featured-pokemon-bonus-7002