Official comment
Yes, a track must be played for 1 minute to be registered as "played" in the history.
Tracks played from an external USB device (call it a "guest" device) are not registered in the local history because they won't be able to be located once the drive is removed. The suggestion has been passed along to log it to the device's history so then you could take that drive back to its home library and import the history, but we don't yet have a timeline for its implementation.