Since Jetpack announced it installs themes, a number of people have asked if this is a violation of the 8th guideline: The plugin may not send executable code via third-party systems.
And in specific, these two items:
Serving updates or otherwise installing plugins, themes, or add-ons from servers other than WordPress.org’s
Installing premium versions of the same plugin
The short answer is no, it’s not, and yes, you could do this too.
The longer answer involves understanding the intent of this guideline, which initially was to prevent nefarious developers from using your installs as a botnet. In addition, it’s used to disallow plugins that exist only to install products from other locations, without actually being of use themselves (ie. marketplace only plugins). Finally it’s there to prevent someone silly from making a plugin that installs a collection of ‘cool plugins’ they found from GitHub and want to make easier to install. Which actually did happen once.
Plugins are expected to do ‘something’ to your site. A plugin that exists only to check a license and install a product, while incredibly useful, is not something we currently allow