The NHL has always been its own worst enemy when it comes to marketing the game. The product they're trying to sell for the most part is solid and is right up there with the NBA and NFL, except the conservative nature of the game handcuffs their approach to promoting their star players.
You almost never see or hear of any feuds, controversy, drama etc. - nothing that generates storylines in the media. Divisional rivalries are forced. Everyone from Crosby to McDavid repeats the same old tired clichés. Players from a young age are told to shut up and keep their heads down, thus you rarely see anyone who actually has a personality like Subban. Why not let players actually speak their mind for once?
Granted, this is not purely on the NHL as this is more of a grassroots, systemic thing. But at the same time I feel they can still do more to differentiate themselves from the other 2 leagues especially on issues like head injuries, domestic violence, racial equality, womens rights, mental health, support for LGBTQ persons etc. For example, we've never seen a single NHL player come out as openly gay, when statistically it is extremely likely there is at least 1 among such a large sample of professional hockey players.
Taking a more inclusive stand on social issues is more likely to draw support from the non-white, straight male population that has traditionally always been their target demographic. You want to attract a more diverse and larger audience, stop implicitly supporting the macho culture that's been prevalent in every locker room since the dawn of time. Start there and see where it goes. There is no losing here.
