Got an email on February 15th saying:
Congratulations, you're eligible for the Amazon Alexa developer hoodie promotion from January. Your limited-edition hoodie is currently being printed and will be on its way to you soon. You can expect your dev hoodie to arrive in approximately 2 weeks. Once it ships you will receive an email with a shipment tracking link.
However I haven't received the hoodie or a tracking link and it's now mid-March. Not sure what happened?