Moto Maker will continue, even after the US plant closes
Well, Motorola has answered at least part of that question. According to Droid Life, Motorola has said that Moto Maker will continue to offer the customization options that you would expect. This will all continue even after the plant in Texas closes down. Unfortunately, Motorola didn't answer the other half of that question: will the build/shipping times be able to stay the same?
It is understandable that Motorola hasn't answered this question yet, because it may not have decided where the Moto Maker assembly plant will move. As we mentioned earlier, Motorola had been looking for a Moto Maker program manager in Brazil, or Motorola may be moving assembly to China to be closer to its next owner, Lenovo. Either way, it would seem reasonable to expect that even if Motorola can keep the build time the same, shipping should be slower.
source: Droid Life