The plugins provided with theme are premium plugins and we purchase an extended license to distribute among the clients for free.
This single key can't be given to every client but for the sake of making sales, these plugin owners urge our clients to purchase New License.
We recommend not to purchase another license because we have given you a valid copy of premium plugins like Visual Composer, Layer Slider and Revolution Slider etc.
We provide updated versions of these plugins in our Theme Update. While launching a new update with updated plugins we first make the theme compatible with latest plugins.
So it becomes necessary to update the plugin when you update the theme. First of all make a backup of your old data, then delete the old plugins and install the new ones, after that update your theme and you are done now.
So please ignore the activation message and enjoy the working of these plugins.