John played in an era that was the highest of all-time for personal assists and steals and that benefitted him. He played in a physical era and that also benefitted him with the ability to clutch and grab.
But John was an excellent ball handler and an extremely efficient shooter to go along with a great passer. Those skills would still translate. But the game is a lot more spread the floor than it was and assist totals for one guy are simply lower because of it (lots of hockey assists). So his stats would not be as good in that regards. But he might score more. He would still be an All-Star.
He would struggle more defensively where the physical play he excelled at isn't allowed as much anymore.