Wild fan here, have watched Granlund for his entire career. Here's what you're getting:
Hugely competitive. Never, ever questioned his effort level. It's high.
Unbelievable skill level, wonderful playmaker. He will make some passes that you won't believe, especially when you see it on replay.
Not afraid to play physical. Doesn't back down, & every once in a while will deliver a hard, clean check of his own.
The biggest knock on him, especially this season- has been his penchant to defer to a pass-first mentality. This got really bad this season, leading to a 37 game stretch in which he only scored two goals. Absurd for a player of his skill level. But also something that should be remedied in short order if surrounded with the right cast of characters.
The reason the Wild moved Granlund is this: His cap hit currently sits at $5.75MM, through the 2019-2020 season. After which, he will be asking for a raise. Fenton had to decide if he thought Granlund was worth upwards of $8MM after next season. If that answer was 'No', which I agree with- then the time to move on from Granlund was now. The closer he got to UFA status, the less leverage the club had. Really, this is all that moving him came down to.
I'd expect the change of scenery to do him well. Wouldn't at all be surprised to see him totally take off in a new environment. I'd expect him to become an instant fan favorite in Nashville. You guys will love him.