I don't want this to seem overly negative. But I really doubt that'd be a good idea.
No coaching experience to speak of. Stopping by and helping out a friend (Tippett) at prospect camp is one thing. Modano lives in Phoenix, it's not like he had to travel. Getting through the grind of a full hockey season is a completely different one.
Questionable leadership and attitude. Modano was stripped of the C in Dallas. It's not like he has this storied legacy of being a great guy to rally behind. Then he took shots at Dallas after leaving. They give him a cushy, do-nothing job in retirement, which he doesn't get to keep when he moves to Phoenix. Then he gets salty again and takes pot shots at Dallas whenever he gets a chance, now.
As far as I know, he's expressed no desire to get into coaching. He relocated to Phoenix and just went to a prospect camp once, for Tippett. If he was coaching high school or something there might be a place to argue from, but he's done nothing but 'be retired player.' And I don't think Minnesota is a great place to try your first hand at coaching at an NHL level.
I question how much respect Modano would command. He only commanded respect when he was at the top of his game as a player. He was never some 'Mr-Intangibles' guy. Maybe some reverence for his accomplishments as an American NHLer, but that's a whole different animal from respecting his vision for the game, and for coaching. It'd be like hiring Jeremy Roenick as a coach.
The former-player-as-GM/coach is a cheap model. It's to sell fans on a management move when the people in charge have no idea what to do. You're going to give Wes Walz a longer leash at coach than some John Doe off the street because you don't want to believe Walz is bad at coaching and needs to be fired and have his relationship to the Wild fanbase strained. That creates two problems:
I don't have a solution to the coaching issue. Yeo's not my favorite, but it's not really on my list of things to fix with the team, either. But Modano is a far cry from what we need.