The hit is massive but it's a relative hit - China probably ends up doing better than the rest of the world because it didn't really lock down everywhere, primarily just Wuhan. And bear in mind, China's government has a long history of doing extreme things that cripple its own economy. That's why places like South Korea and Taiwan were so far ahead (and still are, China's still a poor country). Communism isn't famous for being good for GDP, after all.
Yes, there's a risk of CCP officials getting it of course. The whole 'escape from the lab' theory doesn't suggest it would have escaped at the right time or in the right way. A truly evil government would wait until there was enough vaccine for officials and other important people but not enough for everyone.
I guess any virus theory would assume it must spread all over the world. Given it's not very deadly that doesn't seem like a big deal if the goal is an excuse to establish lockdowns whenever the government requires one for its own stability. Just announce a sudden uptick in cases (a claim which can only come from official stats) and off you go.
I think the biggest reason why the theory doesn't work is that eventually it'd become suspicious because everyone would have had it, and the co-incidence of sudden outbreak at times of civil unrest might become too obvious for everyone. Unless of course the virus is used as an excuse to control mass gatherings permanently.
It'd be like trying to deal with overpopulation by setting a computer program to randomly select 20 of your own population centers to nuke, then launching nukes. Then a week later choosing other random cities around the world to nuke. Plus, it'd probably be discovered eventually, and would obviously be the most severe pre-emptive act of war ever known. It would inevitably cause WWIII, leading to much more death and chaos. It's a completely illogical and self-destructive strategy.
Now, if it were a virus that, say, couldn't infect those with a gene found in all Han Chinese people, and which isn't found in any other groups, that would be worthy of some investigation. Or only infected Uyghurs.
I know this is just playing Devil's advocate, but I think the odds are so low as to essentially be zero, unless the CCP has some sort of bizarre motivation that's extremely distant from nearly everyone else's motivation (like trying to end the world and make humans extinct).