After some further lengthy discussions with Traeger support, it appears the new (not yet released) Meater Probes will work with all Timberline and Ironwood series grills with full Traeger app integration. According to Traeger, this will only work with the newer Meater probes that come with the new Timberline XL grill. So apparently, once we're able to buy the newer Meater probes independently, we should be able to use them with the D2 controlled grills and manage the Meater probe temps via the Traeger app (not just the old Meater app).