There are a couple of key things that indicate this is the Jeep not a Ram, with the first being the two big structural members connecting the cab to the back of a significantly shortened bed. These changes may be there to better simulate how a big solid body will react on the chassis. Also suggesting this is a Jeep is the well-hidden rear suspension that, from what we can see, is probably an independent setup. Since the Grand Wagoneer is going to be a larger, more luxurious counterpart to the also independently suspended Grand Cherokee, this makes sense.
Something interesting is how the Ram body seems to fit on this mule platform without any major modification besides the shortened bed. It leads us to believe that the Grand Wagoneer's chassis will be closely related to the Ram 1500, with the exception of the new rear suspension. This is further supported by the fact that it will be produced in the same facility as the Ram 1500. It would make sense to build two very similar vehicles in the same place.
As previously mentioned, we're expecting the Grand Wagoneer to launch as a 2021 model. Previous spy shots of renderings indicate it will look like a larger, more aggressive, chiseled Grand Cherokee. If it's based on the Ram 1500, it will likely share powertrains, meaning at least a 3.6-liter V6 and 5.7-liter V8. Both will probably come with the 48-volt eTorque hybrid assist system and an eight-speed automatic transmission.