The article misunderstands IPv6 addresses. The best way to put it is that IPv6 offers addresses for 2^64 networks. IPv6 numbers networks, and hosts attach to networks.
In v4, hosts come first and networks second. In v6, networks come first and hosts come second.
What's a first-class and a second-class concept in the architecture.
In IPv4, the IP address is central to the architecture, and the subnet is secondary. In v6, the /64 network is the core, and everything is arranged around that.
In v4, hosts come first and networks second. In v6, networks come first and hosts come second.