Well this question is off topic but I'll try my best to answer. Looking at the Armata project, it seems like the biggest problem is procurement in large numbers. If China ordered them(probably in the hundreds), it is unlikely that Russia can manufacture enough to deliver on time(not sure why, maybe sanctions or financial problems).
There's also the problem with logistics(They will have to source all their parts from Russia like ammo, engine parts etc) - not good in the event of a war. Finally, China has been building tanks domestically ever since they got the Type 59s, never have they bought foreign tanks except for analysis + they're developing a 4th generation tank right now, so... Armata isn't needed (they might even have it in service before Russia could deliver all Armata tanks on time if ordered)
Russia is not Ukraine. Their military procurement is limited by budgetary constraints and not by the maximum output capacity of UVZ. If China orders 1000 T-14Es, UVZ would be more than glad to deliver it on time. The Russian army would also be glad because economies of scale means they also get more Armata platforms of all types including T-14, T-15, 2S35s, etc.
More likely than not, that sort of deal would include having a domestic production line for whatever spare parts might be needed, if not the production line for the tank entirely.
But China buying T-14s is outside the question anyway. For one, it is unneeded and having next-generation MBTs such as T-14 is on the lowest of the PLA's priorities now (pretty much all of PLAGF is low on the priority scale currently). And it weighs around the same as the 99A currently in production. So if there are places where the 99A is too heavy for, then it will also be true for the T-14. That means T-14 can only be the replacement for the 99A, which absolutely does not have a need for an immediate replacement in frontline units right now, nor an immediate need for a replacement in factories either.
When a replacement is finally required one day, there will almost certainly be a domestic next-generation MBT that has finished development and be in mass production, if not already serving in some units already. And only if this is somehow not the case, then will the PLA seriously consider procurement of foreign MBTs as an interim backup solution