In other words, the case is open and manufactured in the US while the part the matters—the motherboard—is proprietary and made in China.
For some context, the EC in most laptops is usually a highly proprietary ASIC (good luck even finding a datasheet) running a blob of proprietary firmware on an 8051 core. It's responsible for handling the power and lid switches, sequencing the powering on and off of the main system CPU, controlling fan speed and temperature sensors, etc.
Please keep that in mind.