Honestly, I think playing in the 80s would diminish Ovie's greatest asset, which is that he skates with the momentum and force of a middle linebacker. He has size, speed, strength and a rocket shot which fit perfectly in this era of hockey. It's almost impossible to legally defend against Ovechkin today, but the 80s 'physical hockey' was far less about next-level athleticism and more about the ability to withstand cheap shots and stickwork, especially in the playoffs. I don't think Ovechkin's combination of size and speed would be as necessary and wouldn't benefit him anymore in the 80s than today.
I imagine if he had trained in that era, he'd be playing more like Kharlamov and less like Esposito.