The difference between plain live rock and "cured" live rock is that the cured live rock is immersed in water and is properly cycled without the die off that regular live rock has.
When you take this cured live rock out of water, wrap it in wet paper, and then ship it for days then you're killing a lot of the stuff that's on it. Sponges, bacteria, invertebrates, and so on. It stops fitting the description of cured live rock and instead just becomes live rock and needs to be properly cycled accordingly, especially since our beneficial bacteria is extremely sensitive to drying out.
Labeling live rock as cured, selling it at a premium, and then shipping it is a great way to con people out of money.