Partially true.
Minion was designed magnificently to include the feature of modules.
By default, Minion comes with one. WoWInterface Addon Updater (or some similar name)
This module enables Minion to interact with the WoWInterface.com website. Let's the user do things like download, install, update, etc.
The grand framework behind, also allows other addon hosting websites to create their OWN interaction module. This enables the other addon hosting sites to choose if they want to expand the usability of Minion to include their site.
In addition to that, a module does not have to be specifically for updating, installing addons. Other examples could be data feeds for WoWHead or ThotBot, or news feeds from various sites.
Now before everyone goes off in a flaming rant, there are lots of security precautions built into the framework of Minion that prevent any types of malicious intent. There have been many posts by the Minion developer himself talking about the SecurityManager.
I hope this shed a little more light on the topic.