This information is related to all plugins that are bundled with our themes. As example lets get a Visual Composer page builder. After theme activation you see a welcome message to install some of the plugins.
After plugins are installed you may see a message that ask you to enter a purchase code (or license key) to activate a plugin. Or a plugin settings page asks you to enter a license key. You can try to enter a theme purchase code but that will not work.
The problem is that buying a theme which is bundled with Visual Composer (or other paid plugin) does not mean that you also buying a license for a Visual Composer. So you just don’t have a license key and can’t activate it or get automatic updates. We bought an extended license to be able to include it in our theme, and we own only one license key (as well as in case with single license), theme buyers are not allowed to use that key, and that is not possible to use same key on more than one site.
In the same time, plugin work totally fine without a key, you don’t need to worry about it. Also, you will get plugin updates as often as theme will be update.