I would recommend adding a text during the installation process or for download or on the installation manual so that developers know about those remote calls. It would be good if it would get clarified what data exact gets transferred as in Germany you can get in real big trouble if your site is sending data and you do not even know about it, nor can you explain what data gets send to whom etc.
This concerns also some other WPMUDEV plugins which are sending data i.e. Hummingbird, Defender etc. - all connected to the HUB.
For Developers and Salespeople it would be good to know what data gets send for what purpose and to whom and how often. Best would be a button to simply disable it - even you would lose functionality, but with that button solution the site owners would be made responsible for their site as they could deactivate the call back phoning home functionalities with one simple click.