The whole premise of replacing ICEs with NEVs is pretty small in the grand scheme of things in relation to emissions, LCA points to 5+ years before they breakeven in terms of emissions in comparison to a ICE vehicle, after which you would get a positive return. Most EVs in China is manufactured in the last 5 years or so, so it wouldn't contribute to a drop in emission, even if we were to consider civilian vehicle emission which is dwarfed by industrial and transportation emission. Most likely culprit to the emission drop is probably what everyone expected and lockdown related, lower level of inter-province transport due to disruptions, slow down of construction sector. For example the production of concrete constitute something like 10% of global emissions and China takes the lions share of that.
Not that I'm critical of the lockdown policies, but there are social and economical costs to such policies, as the other extreme has found out causing widespread recession, it really is just different levels of bad.
Non-paywalled version of the article below
archive.ph/LKVdG