Okay, one thing. This forum generally isnt for automotive questions, with the exception being Car Play from Apple. I wouldnt take any advice from here as real advice. TO get a better answer, go to a real mechanics forum.
As for your question, it will likely roll if left in drive without the parking brake applied and end up damaging parts in the drive terrain, including the transmission and engine. Im not a mechanic, Im not sure how this all works, but that is what I think. Please do not take my word for it.