PLA procurement is different from pretty much every other military's in that the PLA can and does factor in China's unparalleled manufacturing capabilities into its procurement process.
In the event of a major war, Chinese factories can go into emergency wartime production mode and churn out tens or even hundreds of thousands of advanced thermal sights in weeks.
With China's internal transport networks, those sights can be shipped to units anywhere in China within the day of them leaving the factory, and units can perform field upgrades within hours.
With that sort of capabilities and Chinese tech trends, it doesn't make sense to spend millions buying commander thermal sights now, when during a conflict, all frontline units can get the latest sights (which will be better than the best models available now) within days or at worst weeks.
What matters more as far as the PLA is concerned is to have the equipment and in decent numbers.
It's better to have 10 basic models that they can add bells and whistles quickly when needed, rather than have 8 full spec models during peacetime when it will be much more time consuming to produce and train crews up for during war time.
Same thing for night vision goggles, active protection suites and body armour, HMD etc.
1) China does have vast industrial capacity, resources, and infrastructure, but it would still take some time to ramp up the very specific military production facilities, assembly lines, supply chains, etc. Definitely would be a factor in a prolonged conflict, but most likely conflicts will be short. Then again, the number of existing higher tech and capability platforms may be sufficient in any foreseeable, short conflict.
2) Troops also need time to train and familiarize with the new systems in order to be able to utilize them effectively. But perhaps PLA is doing some form of rotational training so that all crews receive at least some exposure to the latest systems.
But overall, PLA strategy is still very cost effective - with such a large army, the cost of maintaining all forces at maximal combat readiness would be wasteful and excessive. Makes more sense to maintain a small yet sufficient number of elite rapid reaction forces using the latest and greatest equipment at high combat readiness, while having sufficient volume and quantity of other still fairly capable forces that can have their capabilities and readiness enhanced within a fairly reasonable time frame if need be.
I wonder what the PLAGFs doctrine for using it's MBTs is - perhaps the Type 99s would either serve as the spearhead of any armored thrust; or perhaps they'd be held as a tactical reserve to support the Type 96s in major engagements against heavy concentrations of enemy MBTs?