From what Ive read, this idea of your body operation on a 24 clock is nonsense. Your body doesn't tun like a clock and so if you ingest that many Kcals in one sitting its bound to put a dent in your appetite for the next day.
Again genetics are a factor, like how much of an appetite you have regularly etc
Yes you are more catabolic during sleep so have an influx of slow digesting protein is a great idea before bed but 1000 Kcals?
Personally from my experience and from what Ive read your appetite sky rockets when your in the weight room seriously moving some Iron. So if you want your appetite to increase id suggest two things
1) Ditch the 1000 Kcal gainer right before bed and add more Kcals in at breakfast and lunch instead i.e. space out this extra 1000 Kclas over your meals.
And 2) Work on seriously increasing your intensity in the weight room, Nate green says if your not physically hungry at least 3 times after hitting the weights then your not going hard enough.