Offering data on the germans embassy site about the foreign government (they do, or rather in the AA, Auswärtiges Amt) is not really the same as financing and organizing political campaings in other countries. And we are still talking about air quality sensor data ..
Yeah, no I understand it sounds trivial and "it's just air quality sensor data" but it's less about what the actual data is about, and more about the intention of publishing something.
I agree that the quest for truth should always trump whatever politics are going on in a country, but the common person doesn't really have that "science" mindset so a lot of the population at large would see something like that as infringement on sovereignty, no matter if what's being spread is true or not.
"see something like that as infringement on sovereignty"
I would ask the people. The stories shared here from Shanghai seem to indicate support of knowing about their air quality. They are the ones to breath it.