Does China still need a Hi-Lo mix of MBTs? I personally believe the direction forward should be a single MBT type.
If the PLA still intends for a Hi-Lo mix of MBTs they should be developing an upgraded 96 or new vehicle to fill the role of the 96, unless they want to develop the ZTQ15 with a package that allows it to fill the role of the 96 or downgrade the older 99s into the role of the 96.
China's military has certain emphasis placed on the ground forces which in turn have certain emphasis placed on MBTs with the whole "King of the battlefield" spiel that keeps getting perpetuated in pseudo official interviews with military people.
This means a tank doctrine that holds significance in planning and thinking ... even if it doesn't displace or replace other platforms and tactics that are superior to MBTs for certain problems. But with this it also means the planners and decision makers are going to want to have MBTs of varying weights mostly for varying environments - landscapes, soils, bridges, street types, widths etc etc.
The rest of the question is really all about industry, resources, and financing. PLA reckons it's worth building the three current tank lines with two MBTs which surely share some commonalities. None of those three production lines have been stopped. For future MBT, one could argue that there are currently no piece/s of technology that warrant the development of any new generation of MBT. T-14 isn't taking things
that far. If there's realistic and viable invisibility cloaks, far superior APS, engine/drivetrain tech then maybe yeah can see all the major powers invest in a proper revolutionary generation of MBTs making use of those technologies but right now they are there to fire a big round, counter other heavy armour, and hold positions. They're not even that great these days for storming in like the cavalry used to. Even NATO >60T would get (and have been) swatted with ease if inadequately supported or even if up against any remotely decently equipped opponent like... Ukraine, Yemen, Libya...