The cancellations are because of rising prices, that doesn't mean they can get fuel, just that the current price makes the destination unprofitable. (Technically this should free up some fuel).

But I was thinking from a political perspective, allowing airlines to just fly destinations that frankly aren't needed, like vacation hotspots, seems ill advised, if you truly expect to run out off fuel. The reality is that Europe won't run out of jet fuel, it's airlines can pay for the fuel it needs, for the destinations it requires, but prices will go up. Poorer countries will run out, because the fuel is worth more in Europe and will be redirected.