Do you have a source? I do not see where the supply will come...

Do you have a source? I do not see where the supply will come from for them to stockpile anything above historical averages. Russia is shut out and their local mines have also been shut thanks to the green movement. Also, Europe does not buy from Australia and Rotterdam futures show little demand. India, China and Japan are struggling to source supply for their seasonal demand let alone stockpile for demand far out into the future. China did have stockpiling issues with speculators some time ago, but they squashed that, and coal price went down a bit but has since rebounded above the initial price.

Despite the softer northern winter (with US as the exception), the coal price is still strong. Our current summer is mild, and I have noticed that when our summer is severe so is their winter and vice versa. Where I am we have not had anywhere near 40-degree days since this summer began which is very unusual compared to the last few years.

You may have also missed the news that polish citizens are digging up coal in their gardens with shovel and wheelbarrow to supply a hungry market. Many are making more from this than their day jobs. With this kind of demand there is no logic in stockpiling. If anything, stockpiling should occur when prices are low.

Indonesia sets Jan coal benchmark price at $305.21/T -energy ministry | Reuters

Lower quality Indonesian coal is trading higher, an increase of ~10 since Dec 2022. Global supply cannot keep up with demand. China will likely start sourcing coal from Australia by the northern summer. If they push for coking coal, it will put even more pressure on prices because majority of suppliers have blended their coking coal to suit thermal boilers due to the price disparity of the two. This could again push coke prices above thermal prices, incentivizing producers to take away from the thermal market to supply the coking market. This would push thermal prices higher in tandem with coking prices.