This is a complete bullshit measurement.
They were on vacation and stopped production for a few weeks. They are turning production back on to catch up for halted production.

Even if that sulphur is only from bodies, maybe they were just stacking up while society was shut down?

Even then, ~833,333 people die every month throughout China for all sorts of reasons.

Adding 75000 a month (numbers 100x the reported covid-19 fatalities), would only increase it by 8%.