That is great advice.

All coatings will pass moisture in the air, and stabalize to the ambient humidity. So if you left your arrows in an unheated place in a wet fall they could absorb enough moisture to get out of the zone where they have the right humidity for maximum strength/stiffness, and the spine could suffer. The actual correct humidity range is pretty narrow, though consistant with comfortable living conditions. The same problem can occur with extreme heat. So, if you want to be super careful you can epoxy seal arrows, with marine epoxy, I've done it, and would only do it again if I was going to some place where it rained 24 hours a day. You have to use an epoxy with 100% solids or it is permiable like gore-tex, and the process is a little messy. Even then, over a longer timeframe, they will stabilize to ambient conditions.

The simpler thing is to store your arrows at "room" conditions, return them there daily, and follow AP's advice.