SinoSoldier
Colonel
I do not have the slightest doubt that Javelin and NLAW will penetrate most if not all modern western tank (includes Type-10 and K2). Its how the internal arrangement that decides the fate of the crew. I have fear that 99A will suffer from the same fate as T72/90 in Ukraine if measures are not taken. Either you come out of insensitive propellant, or install APS. Blow out panels are out of question on tanks with carousel loader. Change of doctrine/tactics may help, eg mopping the area with thermals equipped UAV/drones, or sending in unmanned combat vehicles like Uran-9. Some people have pointed out that the convoy ambush footage released earlier was a booby trap/ remote trap. That does complicate the situation.
The Type 99 was developed on the basis of Soviet-era vehicle configurations so if the PLA deems the top-attack threat to be severe enough, the only recourse would be to develop and incorporate a hard-kill APS that also covers the area above the tank. The advantage of investing in a hard-kill APS over redesigning the MBT altogether, other than cost, is that the former will also prevent a mission kill of the MBT (you save both the crew and the vehicle).
That being said the Chinese have been experiencing with newer & Westernized tank configurations such as the ZTQ-15, so they may very well be choosing to develop a clean-sheet MBT based on the layout of the ZTQ-15; this would explain the lull in the introduction of newer Type 99 variants.