I know nothing about tanks, but are these tanks used for guerrilla warfare? Obviously, they have the characteristics of high speed and stealth, such as hiding near cities or mountains and relying on sky intelligence for rapid assault operations? Does the lighter weight also mean that this car is cheaper and more able to withstand losses?
Chinese doctrines don't seem to priorities city warfare with their tanks, they'll use IFVs for those. But potentially these new tanks with addon armor could also do well in city warfare. Lighter weight of this tank isn't really indicative of its protection levels, since there are pictures of this tank with heavy addon armor that supposedly brings up the weight to 50 tons which is basically the normal weight of MBTs. But this modular design means this tank could replace the 99As up north, 96As down south and ZTQ-15s in the west all at once since without any addon armor modules this tank would weigh about as much as a ZTQ-15 which makes it suitable for mountain warfare in the west and with heavy armor addons I believe the crew protection would be at least as good as the ZTZ-99A, probably alot better because most of the 50 tons is going into the hull due to unmanned turret being much smaller and not needing heavy protection(Probably good enough to withstand next gen NATO autocannon rounds) since no crew is in there. ZTZ-96As would probably be replaced by this tank with normal armor addons to keep its weight at 40 tons-ish to traverse soft terrain in the south. As to the cost of this tank, it should be quite expensive since it uses advanced technology like unmanned turret, next generation thermals and sensors which all cost a fortune.
tl;dr: This tank IMO will be a true universal tank that can replace basically tank in PLAGF service with different addon packages and protection level of this tanks with their respective packages should be at least as good as the tanks they will be replacing. Potentially there will also be a specialized kit for city warfare similar to the TUSK kit for the M1A2 Abrams, but I'd imagine this kits for this tank to be more comprehensive than a mere "addon" kit due to how modular the design is.

This is speculated to be the tank with heavy armor addon kit, see the heavy composite blocks on the side and fenced armor covering the engine and with heavy addon LFP armor in the front. Notice also the APS seems to be able to be retracted potentially for better low observability. Speculated to weigh ~50t

While this is the speculated to be the "base" configuration with no external addon armor of any kind. Speculated to weigh ~40t. Potentially with modular internal armor, more armor could be removed to further reduce weight to ~30t for a light armored configuration to replace the ZTQ-15.