Skype example proves exactly the opposite: the main reason they had to switch back to a centralized setup is because as mobile became a more dominant usage scenario P2P became untenable. Supernodes had to serve quite large and -- worse -- constant traffic which kept them alive (draining battery and consuming data).
From the article, it seems this is not a true p2p architecture. It's more of a hub and spoke model, with each phone connected to the cloud, but not to other phones.
