Think about it. This town can't have been the only place the toys got shipped too. What happened everywhere else!?
Answered in movie, Original-Chip got reinforcement from the mall the rest were shipped to, the implication being that only Original-Chip was activated early. The Rest were probably recalled.
It's actually a good thing the original toys got found out on this small scale before they were shipped out - especially if they can bust out of their own cases.
The climax of the movie involves an electromagnetic pulse that we see cover the entire neighborhood. In a previous scene, we see an elderly couple turn the volume up on their TV to drown out all the noise outside. What if one of them had a pacemaker or other electronic device as a necessity?