The missing components mentioned by AMG consisted of certain tokens and cards from the 501st Legion and Separatist Invasion Force sets. This was the result of a print production issue involving the cardboard components. Customers replying to the Twitter thread (see below) also mentioned not having enough plastic "flying" stands for the miniatures included in the boxes. Some of the customers replying to their Twitter announcement didn't know that some of the parts were missing until AMG posted up the note acknowledging that components were not in the boxes.

AMG has offered print-and-play solutions the non-essential missing components on their website. They have also planned a production run specifically to fix these issues, and updates on this initiative will be forthcoming.