The winter season is harsh these days in the US. Winter storm Dion has hit the US badly. A large area of the country is facing heavy snowfall. And this severe weather affects the deliveries too. Google's Motorola is also not able to ship devices in such a cold winter. Neither is Motorola able to ship its Moto G devices on time.
The company has sent out email notifications to those customers who pre-ordered the Moto G on launch day. Motorola meanwhile has apologized since it cannot ship Moto G on time. Moto G deliveries will be delayed due to a winter storm. This storm also struck the fulfillment center in Fort Worth, Texas along with some other regions. Hence, Moto G shipments will be delayed. Moto G was to be originally shipped on December 4th.
Motorola states in its shipment notification email that "your phone order wasn’t shipped according to the original estimate. We sincerely apologize for the delay and want you to know that your Moto G will ship by December 17th via a free upgrade to our overnight delivery."
Source: Android Central