We know that Kid Nocon is currently working on Shenmue III, most likely modelling new environments like Bailu Village and Choubu. He has already modelled a large section of Dobuita and the Hazuki residence (at least the outside) using the Unreal engine just for fun, so wouldn't it make sense to incorporate them somehow?
My idea would be to create a playable flash-back. For Dobuita, you could walk the streets on a dark and stormy night (which would explain the lack of NPC's) in order to meet Nozomi at her flower store, or something similar.
I don't think it would take a huge amount of work and would allow players to experience a remastered Dobuita and Hazuki residence, albeit in a limited way.
Kid Nocon's video:
https://www.youtube.com/watch?v=g7cjDaOQpB0