No, he wouldn't. He would struggle alot more in his prime than during these days. The game is alot faster, defenders aren't allowed to play lumberjacks (to his advantage), 4th lines aren't a joke with a goon gliding on the leathers of their skates to try to approach the other goon for the staged fight. They are actually an offensive threat given a chance and know how to play hockey. Goalies are infinitely better, teams actually have a system to defend and defensemen can actually skate, know how to block shots, cut off passing lanes and where to position themselves.
I get that you want to romanicise how things were, but no. Gretzky would never be close to his records against full pro teams, Lemieux would never have his scoring streaks and Jagr would never be able to dominate as he did. Just no.
Players like Gretzky, Orr and Lemieux were ahead of their era, but where they better? Heck no. They would still be stars, they would still be generational, but they would never produce the points they had, not even close. The reason they are seen as truly greats is because they were generational and ahead of their era, but they did play in a hockey game that was kind of a circus compared to today.
NHL players today are too well trained, too fit, skilled and smart enough that the absurd numbers during previous eras will never, ever be established again, because now they are actually professional teams down to the last line at 200 ft of the ice - and in the net. Even below average goalies are infinitely better than most goalies during previous eras. It's impossible.
That's why you can't compare players to different eras. It's a completely different game.