I have an aussie gold torch and can say that mine does do this regularly and it seems to be directly related with the transition to low light. It will slowly recede after peek light hours have passed and may stay semi-retracted with some skeleton showing for an hour or so before coming back out to about half its daylight spread before the lights totally go out. I've noticed that some of the polyps remain nice and fat even though they are barely peeking out during the recession stage. I upgraded my Biocube lights to steve's leds lately and I am only about halfway through the acclimation process. My aussie gold and my other two torches all crave more light because during the day they are super full like you are describing, a couple of the torches are semi transparent in body and polyps. My understanding is that this is a sign that they are not receiving high enough intensity light and are stretching out to get as much surface area as possible. I still expect to increase my intensity by approximately 35% more over the next month or so.
I personally don't know if corals recede in this way at any point during their daily cycle in the wild. I am curious.