There is no need to worry because we apparently don't see "real progress" or advanced content, that doesn't mean they are behind the schedule. I'm sure they don't want to show how advanced Shenmue 3 is and they are showing old prototipes they used and such. They must be very advanced in the project and only show dated material.
Besides, maybe they are waiting for the next Magic Monaco or E3 (this specially) to show an actual "work in progress" trailer with the new model of Ryo and more things..