The van is designed to carry seven adults, If you assume each adult weighs 200 pounds, you can assume the van can carry roughly 1400 pounds. If the driver is the only one in the vehicle, you can assume a 1200 pound trailer is adding little to no additional stress on the vehicle. Anything over that would be extra stress and most modern vehicles can handle at least half of their designed weight above its own in normal/ the average conditions.
My scenario is a bit on the extreme side, but towing 3,000 pounds for more than 120,000 miles with a fully loaded van, rooftop box, 3 people and 3 dogs, my van shows no signs of any issues. I keep up on maintenance and monitor trans heat to make sure.
My last non-hybrid Pacifica had trans issues before 60k miles with light towing. 900lbs trailer, but it was rated at 3600lbs. I think I had a defect, but luckily it was covered under warranty. Just sharing my experience to compare.
Hopefully this is helpful for some.