When Traeger announced its 2019 lineup, it included its so-called WiFire wireless connectivity on every model. However, the sensor that monitored your pellet supply so you didn't have to worry about running out was reserved for the priciest grills: the Timberline 850 and Timberline 1300. As I'd discover in November, the more affordable Ironwood and Pro Series grills were designed to accommodate the sensor, it just wasn't included on those models.
It's unclear if Traeger is simply including the sensor in the box or if it's installed on the Ironwood grills already. Even if it's not, the installation process is quick and easy, and should take you 10 minutes or less to attach and connect.
And yes, a pellet sensor is a handy addition to these grills. Without it, you have to walk out to the grill, lift the pellet hopper lid and manually inspect things. With this sensor, the grill automatically monitors how much is left in that container and displays a percentage inside the Traeger app. That info is shown alongside things like grill temperature, probe temperature, cook timers and more. When you're running low, the app will send you a notification so you know its time to add more or make a quick run to the store.