You would be incorrect. I have no connection with ADT and my only connection with SmartThings is as a customer.
Also, you are responding to a thread which has not had any activity for at least a year, and much has changed in that time.
Noonlight requires an active Internet connection to send notifications. As I have said many times in this forum, my own minimum requirements for a security system, even a self monitored one, is that it have a cellular option for communications.
I have never recommended ADT itself as a security system, here or anywhere else. In this forum, and only this forum, I have recommended the dual logo model as a candidate for further research for some specific projects.
At one point ADT and SmartThings offered a “dual logo” system
This was the only SmartThings-based system which offered cellular-based communications, as well as the ability to arm/disarm locally. So I did suggest that it was the only SmartThings-based system I would consider as a candidate for an inexpensive security system. But I still almost always recommended that people consider other options as well, including Abode and Simplisafe and now Ring. Each offers different features and plans, but at least all 3 of those have cellular notifications to the monitoring center, which SmartThings to Noonlight does not.
Everyone has their own peace of mind requirements when looking at security systems, and many people really do want to limit themselves to something that integrates with the Samsung SmartThings ™ platform. Over a year ago when this thread was last active, the ADT/SmartThings dual logo system, which is a specific model, was the only official SmartThings-based option with cellular notification.
There was also an official integration with Scout and a number of unofficial integrations including noonlight. However, all of the others require that both the Internet connection and the SmartThings cloud be available. The dual logo model did not, hence my comments in this thread.
See the official links on security. Again, this is one specific model line manufactured with both SmartThings and ADT radios built in. (Although just to make things even more confusing, it was a different ADT radio than the one in other ADT models.)
https://www.smartthings.com/home-security
However, all of that said, since then the Scout partnership has been officially discontinued and the dual logo system moved to End of Life status, so I no longer recommend it even as a candidate.
Submitted with respect.