Is the crux of this article just that the Chinese oil reserve is 2x the capacity of the US oil reserve?

Is there anything more to it than that?

Which makes sense. The US is a net oil exporter -- in a strategic emergency the US will still have access to oil. China will want to have a much larger buffer, since its economy requires oil from other countries.

They were also able to drastically cut their own internal demand and external sales/shipments (the article mentions jet fuel to other Asian nations).

This was possible because their economic planning is centralized.

4x. The crux is that they can flip a switch to change global oil supply, be highly resistant to embargos, and are no longer subject to OPEC (through Iran & Russian oil traded in Yuan). They can now change global oil prices at will and resist attacks on their energy imports.