I think the confusion here is in the interpretation of the switches. Note:
-i, --ip-address addresses for the host name
-I, --all-ip-addresses all addresses for the host
The lowercase i (-i) will list all addresses that can be resolved with the hostname, so, for example, your hosts file will contribute, in addition to whatever DNS resolves. In some (corporate) networks it is common to run an internal name server for hostnames on the local LAN. These addresses do not need to be "real" or in use, they are just records against that hostname.
The capital i switch (-I) will return current interface addresses associated with the host, which should match up with an "ip address" command.