Could be, although fairer is probably not "worse". But indeed it could make commodities more expensive. Maybe there is a short-term vs long-term consideration.

Based on descriptions by Alex Gladstein, the IMF effectively "captures" poor economies so that they end up being forced to produce commodities not of their own choosing/interest, but chosen by the West. I don't know if this is true, but let's assume it is. Then such a country would have strongly misallocated resources, its economy being highly unproductive because the incentives suck. If many countries are in this situation, the world is presently full of highly inefficient commodity producers.

Now let's assume that these countries are (somewhat magically) freed from their shackles under a bitcoin standard. Logically, they would wind down their monoculture production of commodity X for the West, and start producing whatever they can derive the most value from, where they have a competitive advantage. Commodity X would decrease in supply, affecting prices paid in the West (and everywhere). But if X goes up substantially in market price, more producers will join. Perhaps some of the "freed" countries would be willing and able to produce X even cheaper than what it was available for before. In addition, they would progressively add more overall value to the international market than before because they produce more efficiently.