Yes, of course it's possible. The thing with McDavid is that, although he's the best player in the league, his level of play isn't such that he's going to win an Art Ross/Hart every season. His consistency will have him in the running every season (and that's what makes him the best) but he's not good enough to consistently pull away from the field. This year Draisaitl beat him, the season before that it was Kucherov and the season prior to that, when he did win an Art Ross, Crosby had roughly the same PPG but missed time.
I think Draisaitl, MacKinnon, Crosby, Kucherov, Kane, Pastrnak, etc. and eventually guys like Pettersson and Matthews are all capable of putting up a big year and "stealing" a title from McDavid. It would be difficult for Draisaitl, since he plays on the same team and they share so many points but it's definitely a likely possibility.