I've had the effect, but never used creatine. It happened when I was trying veganism - in retrospect, not a healthy move, but I think it was calorie restriction that caused me to need less sleep.

what makes that effect more than anything else in my experience is phenylalanine and tyrosine, tyrosine is probably the better one if you are going to pick just one the creatine may be assisting you to maximise your intake of these catecholamine precursors, you can see it if you read about those two amino acids, they are notable for reducing sleep need

i should point out, though, that if you consume it later than 3 hours before sleep it makes you wake up frequently from dreams, you need to eat it earlier in the day

There might be something to what you're saying because, alongside creatine, I've also changed my eating habits. Instead of going vegan, I'm now following an 8-hour eating window, which definitely means I'm consuming fewer calories.

I'm doing the same. It worked great at first, but I've been gaining weight again lately. I started eating more, just keeping it in the eating window

useful info, that ^

I take around 7g every day and I definitely feel the difference when I don’t take it!