The ORD de-ice is not a Skywest policy. It's a United policy. United does not want you to be called "out" until you're within 60 seconds of actually moving the plane. It is the policy they impose on all the UAX carriers that operate out of ORD, and it's because de-icing is done at the gate, should it change to a remote area, then you're obviously going to be on the clock since you taxied the plane there.
I think it's a crap rule. No, I do not agree with it, but I am clarifying it, since some think that it's something Skywest management conceived on their own. Direct the blame at United management for that one.