It promotes a calorie deficit because it would be difficult to stuff your face with an entire day's worth of calories in a matter of 1-2 meals. Unless you derp by eating certain fast food and processed sweets/desserts, then yeah, easily achievable to surpass your maintenance calories.
The way intermittent fasting is supposed to be used is that you just straight up skip your meal or meals, and then you pick up on the meal that you start eating again as if you had had those other meals.
Don't use intermittent fasting as an excuse to eat a 2400 calorie dinner and you will lose weight because it created a calorie deficit.
The point of intermittent fasting is that during the fast your metabolism increases and your body enters partial ketosis which is beneficial for healing and general well being.