Do we know if the hull would be around the same or would it be a new design entirely?
It does not sound like a hull change buy a new production batch. In my opinion, the 052D is a mature platform maxed to the hilt but ripe and there's room for a few more minor changes that can further enhance its defensive capability.
For example, it's time to retire the Type 364 radar on its top mast and replace it with a new radar, which is the small dual sided AESA we see used as a secondary radar on the Type 075.
Or they can go more radical and replace the mast with a new integrated mast with new fixed secondary radars and other sensors.
Another minor update is to upgrade the CIWS to the one we saw on the Fujian, which mounts a small phase array.
They might also introduce a new fire control radar to replace the Type 344 gunnery and 366 antiship radars. Like the 364, these are still mechanical radars whose designs are over decades now.