I just upgraded to the latest Fedora Atomic 24 Host with today's release and it seems that the recent commit still hasn't updated /etc/os-release:
[fedora@atomic ~]$ sudo atomic host upgrade
Updating from: fedora-atomic:fedora-atomic/24/x86_64/docker-host
No upgrade available.
[fedora@atomic ~]$ sudo^C
[fedora@atomic ~]$ cat /etc/os-release
NAME=Fedora
VERSION="24 (Twenty Four)"
ID=fedora
VERSION_ID=24
PRETTY_NAME="Fedora 24 (Twenty Four)"
ANSI_COLOR="0;34"
CPE_NAME="cpe:/o:fedoraproject:fedora:24"
REDHAT_BUGZILLA_PRODUCT="Fedora"
REDHAT_BUGZILLA_PRODUCT_VERSION=24
REDHAT_SUPPORT_PRODUCT="Fedora"
REDHAT_SUPPORT_PRODUCT_VERSION=24
[fedora@atomic ~]$