Bringing meat to room temperature by leaving it out is a bit of an old wives' tale. Kenji Lopez-Alt definitively disproves it in this article. And that's about an inch-thick steak, so it's even more true for a large chicken.
On the other hand, leaving a chicken uncovered in a refrigerator accomplishes two important things:
- It dries out the skin (especially on water-chilled birds), making it easier to render off fat and thus create a crispy skin; and
- When transferred to an oven directly, it keeps the meat cold for longer when the chicken is in the oven, giving more time for the skin to crisp before the (breast) meat gets overcooked.
Interested in other tips? Check out my ultimate recipe at My Quest for the Perfect Roast Chicken.