A few changes to the way the setup module works, which are pretty transparent to everyone, unless you wrote some code that was reading
that file.
(A)
Ansible no longer writes a setup file to the remote system. This means you have to use the template module only within playbooks.
(B)
Ansible will only run the setup module once per play now, even if you are using vars_files. This is much faster, and saves duplicate work
on nodes.
(C)
Ansible no longer pushes all possible remote variables into /etc/ansible/setup. This means ansible remote machines never see all the
variables you make available to them, only what they need to see.
If you want to see what facts are available to a host, that's still there, just run
ansible hostname -m setup
And you can see them.
--Michael