No, the process I mentioned does not update the hostname. The described scenario works in a situation where ntp.example.com has initially only an IPv4 address and is in the pool, and then later on an IPv6 address is added to the same ntp.example.com hostname.
If you wish to update the hostname to, say, ntp-v4.example.com, it’s possible to ask that from NTP server support people, or just delete & re-add the server with the new hostname.
Besides, it’s 2018 already and IP version specific hostnames are soooo old. ntp.example.com with both an IPv4 address and an IPv6 address is the way to go.