I agree that Hunter is more likely than Mauer. Hunter does still seem invested in the game.
And frankly, he'd be a better choice. Mauer is the local hero, but he's staid, quiet and prefers to keep his insights to himself. Or at least, that was how he was as a player.
I understand that this appointment may be more of a figurehead status, however, this role could still lead to league-wide exposure and possible talent recruitment; the outgoing and very connected Torii Hunter seems to be a better choice.
And not that I think this person will have the pull, but if you had to choose between Mauer or Hunter into talking the majority owner into opening up the wallet for free agents, Hunter seems to be the hands-down better choice for that.