This article is largely about IPv6 in internal networks, not IPv6 in the internet as a whole - as they say, "No one uses IPv6 only. All public network operators, and nearly all private ones, must offer full compatibility with all other network operators and as many end points and applications as possible." Their three choices are about remaining on IPv4 only, running dual-stack IPv4 and IPv6, and using a translation layer to run IPv6-only internally and convert to IPv4 at the border. All of them involve public IPv4 addressing, and the assumption is that the internet will forever be IPv4.
So this means two things. The first is that the desire to move to IPv6 on the part of the article's authors has nothing to do with public IPv4 address space exhaustion, it's based on other alleged inherent benefits of IPv6. The second is that IPv4 NAT already solves the exhaustion problem - you're either doing NAT to IPv4 or NAT to IPv6 (using your favorite 6preposition4 encoding/tunneling scheme), but as far as the public internet is concerned, it looks like you're doing plain old IPv4 NAT.
So this means two things. The first is that the desire to move to IPv6 on the part of the article's authors has nothing to do with public IPv4 address space exhaustion, it's based on other alleged inherent benefits of IPv6. The second is that IPv4 NAT already solves the exhaustion problem - you're either doing NAT to IPv4 or NAT to IPv6 (using your favorite 6preposition4 encoding/tunneling scheme), but as far as the public internet is concerned, it looks like you're doing plain old IPv4 NAT.