We have a 2017 Imagine 2800BH that we tow with a 2013 Expedition EL 4WD. I would stay away from that trailer with the Expedition and here is why. You are most likely going to exceed the payload capacity for the Expedition. When we travel at full load, we have 2 adults, 2 kids (7 and 16), and 2 dogs (35 lbs and 80 lbs). We are under our weight on payload but not by much, and this has been verified using the CAT scales. Our 2017 2800BH as built came in at 6204lbs dry, a few hundred lbs higher than Grand Design's at the time advertised UVW. This is because the manufacturers list is typically an average and doesn't factor in different options. Most likely the 2970RL you find will be higher. Also, I wouldn't go any heavier of a trailer with the Expedition than what the 2800BH weights. We are under payload and total weight we are at about 85% towing capacity, which most will recommend 80% for safety and wear and tear.
As the poster above mentioned, 8900 lbs for a 2013 Expedition 2WD is the max only if it comes built with the OPTIONAL HD Trailer Tow Package. Pretty simple way to know if yours does, if it has the factory brake controller in the dash, it was built with the HD tow package. There is also a Ford site that you can enter your VIN and it will provide you the build specs for your vehicle.
Why not look at the 2800BH? It's a fantastic floor plan for a family. We never feel cramped when our family of 4 and 2 dogs are all inside at the same time.
