The same electrical potential may still be present in the clouds, but instead of being neutralized dramatically it could now be dissipating slowly rather than gone in a flash :)
More study would be good to have.
I wouldn't jump to this lemma so quickly. The paper mentions the density of aerosols. Sulfur oxides promote condensation by forming low-volatility compounds like H2SO3 and H2SO4. An increase in the number density of droplets could mean more triboelectric charge transfer between the droplets and the air. That would increase the amount of electric energy in the clouds.
This is also the mechanism by which sulfur has been proposed for geoengineering, but I think the variant that replaces sulfur with terpenes sounds safer.
I expect it's related to how lightning is triggered, not changes in atmospheric charge due to conductivity.
Problem is, atmospheric science isn't exactly considered "high status" vs the other two.
That was my initial thought, like a “phantom power” drain, the process by which electrons knock each other is able to happen in a broad manner, not concentrated in the poles and suddenly discharging among a single path, i.e., lightning.
It seems similar to how static electricity builds up easier in dry environments because in humid ones the electrons can more easily equalize across water molecules.