Winter for the Ages: Cold War Rush (1/21 - 2/4/19)

[Bobortvogel]

What’s even funnier is the the silo upgrade is highlighted under the event inside the game.

 

[alegs]

Hint: The silo without the 50% price reduction will cost more oil than the atomic refinery can hold.

 

[Manifesto]

I think because it was added in the recent 6.7 update. It probably wasn't part of the original plan for Winter event.