Welcome. Typically, it's because of low sales of a particular color... My last GM I was set on a charcoal gray, but they stopped making it in sometime around 12-13 I think which really upset me.
Well.. I haven' had mine fall so I don't have any insight to how it's supposed to be behind that panel. but, I have noticed a they're a little slower when its colder but I'm in TN, so we don't get that cold here.