Considering that a pc-12 is such a great heavy haulers...have 3000 hrs in them....and often I was HAPPY we had two bigger guys in the cockpit...helped us from being too tail heavy.....
If it fits it flies, often with seats full (6 seat exec configuration and almost 6 hrs fuel on a dual battery plane, itself kinda rare outside of some specific operators). I kinda doubt the life support equipment is THAT heavy....
It's their company...but I suspect the weight limit is more about being an underhanded way to keep a "professional appearance" look without the legal issues of discrimination.....