My identical recollection of the MIJ Metro Express instruments when I purchased mine. In post #63761, Kai posted an excerpt from Roger Sadowsky. It stated the following:
The MetroLine began in 2003 and eventually duplicated most of my NYC models. They all featured Japanese-made bodies and necks. Sadowsky preamps, pickups, and bridges were used. They were not chambered. Production was ended in 2020.
The MetroExpress was made in Japan from 2017-2020. This was a full-on factory-made Sadowsky in only the 4-21 and 5-21 models and the 4-24 and 5-24 models. We also did the Verdine White model. They were chambered. Production ended in 2020.
I wondered why the MEs were about 1 lb lighter than the similar Metroline instruments, and this is more than likely why. I never knew it was chambered until this post.