Hi Jason,
I am afraid the wiki page is incorrect regarding the ntpd_t type, and the selinux policy lower on the page is not something which I would recommend to use.
The ntpd_t type is a domain type which cannot be assigned to a file. I am not aware of how the feature works so I cannot suggest further.
Note in current Fedora there are chronyd and systemd-timesyncd services for time synchronisation. The chrony.conf man page suggest to use
ntpsigndsocket /var/lib/samba/ntp_signd
so it may be sufficient to leave it as is. If there is a regular service running in the initrc_t domain, it should be confined by SELinux, but that is a long term solution.