I have tried installing moodle on xenial (not with synaptic though) and I got this message:
"The moodle package does not perform any automatic web server configuration, but does provide basic configuration templates for Apache."
That's true: the installation process just creates two template files in /etc/moodle/ (apache.conf to integrate moodle in an existing web server, and apache.vhost.conf to create a virtual host dedicated to moodle). It's up to you to add one of these files to your Apache configuration.
I have tried installing moodle on xenial (not with synaptic though) and I got this message:
"The moodle package does not perform any automatic web server configuration, but does provide basic configuration templates for Apache."
That's true: the installation process just creates two template files in /etc/moodle/ (apache.conf to integrate moodle in an existing web server, and apache.vhost.conf to create a virtual host dedicated to moodle). It's up to you to add one of these files to your Apache configuration.