The strategic oil reserve is crude oil. It has to be sent to a refinery before it can be made into things like jet fuel. Some refined products don't have a long shelf-life so it is only manufactured to meet demand.

That "6 weeks" probably reflects oil that is already in the refinery supply chain and is therefore deliverable over the next several weeks. The issue is that the top of that funnel is not being refilled.

The US is an exporter of jet fuel but places like Europe and Asia or more exposed to bubbles in the supply chain.