They are already extending HDZ shipyards at Changxing. We already have Phase 1. Phase 1 has already been active and is constructing ships to customers right and left. The extension adds Phase II to the project.
Selling the shipyards at Huangpu river is going to net a tremendous amount of Yuan, and given the rising real estate prices in the Shanghai metro region, the amount of cash you're going to get from auctioning and selling it isn't going to be matched by years of meager profits in shipbuilding. This is the sole shipyards left in the Shanghai proper; every shipyard that used to be located in Shanghai has already sold out their traditional locations and moved to an island somewhere.
Good too, because the river is crowded and is an accident waiting to happen. Imagine if you bought a brand new Tesla but the road straight out from your house is a busy Asian city traffic intersection, and the car also has to be parallel parked along the same streets. Even if the pilots are highly skilled, there is no doubt there is going to be significant mental and psychological stress to those navigating and piloting the ship. Not only is the river crowded with all sorts of ships and boats, it snakes continually. It says a lot that the captains, pilots and navigators of ships that transverse the Huangpu and the Yangtze, have great skills.
The bigger the ship goes, the less maneuverable it gets. When HDZ was building 053s, then 056s and 054As it probably wasn't that big of a problem. But when you start to get to build 071s then it becomes a bit of a problem and seeded that intent to move elsewhere. When the first 075 moved to its trials and floated down the river, there is probably a lot of anxious and stressed people at HDZ. Imagine if the ship collided with one of the many cargo ships, ferrys, and trawlers around the area. If they are planning to build 076 and larger LHDs, its going to be likely from the HDZ Changxing Phase I or II now.