I think he'll get in if he does win the Cup and Conn Smythe this year (certainly far from a given), assuming he compiles points for a few more seasons.
I've always liked Hall as a player in the NHL, but his prime does leave quite a lot to be desired. He wasn't the most consistent star (nor did he have Sundin-like health). Despite that, I don't think they'll leave out a player with a Cup, Hart and Conn Smythe. He also has a fairly high profile because of his junior career and the fact that he was a first overall pick.
People saying he doesn't belong or has no chance may not realize how low the bar is. I'd rather have a multiple major award winner who led a Cup winner in playoff scoring in there (only a hypothetical for him right now) than a guy who scored ~35 goals a bunch of times during the NHL's highest-scoring period but never competed for any major awards or made significant contributions to a Cup-winning team.
That said, his Hart had a lot to do with circumstance, and his Conn Smythe (if he wins one) will be similar. I was okay with the fact that he won the Hart in 2018, but he wouldn't have if the Oilers had made the playoffs. A few guys had legitimate cases that year (he was one of them). He hasn't been the best or most valuable player in the playoffs this year (Marner has obviously been better, and I'm not sure Hall has been second-best), but with Carolina's top line shitting the bed offensively throughout the tournament, he may end up leading a Cup-winner in scoring.
