If the larger mining nodes despawn, there is still the old method of mining to fall back on. I don't know how the anomalies work in the slightest so I feel I should ask, is there another way to get their resource once the server NPC cap is reached? Do they suffer from the same despawn issue? If my assumption is correct, the despawning is a far more pressing issue for the anomalies than it would be for the mining, and yet the more problematic of the two has already been implemented.