Ah. There’s a bit of confusion here. We make a distinction between eating to satiety and restricting calories, because intentionally restricting calories has the risk of being counterproductive by depriving the body of energy it needs. That would, in truth, be a calorie deficiency, and the body responds to it in ways we generally do not want.
But one of the benefits of a well-formulated ketogenic diet is that it restores appetite as a reliable guide to how much energy the body needs. So if we eat to hunger (satiety), we will eat at a level that gives the body an energy abundance, and that abundance will come both from the food we eat and from our excess stored fat (remember that a certain minimum of stored fat is required for safety’s sake, around 10-12% of body weight for men, around 21% for women). As you correctly state, this by no means constitutes a caloric deficiency, and I argue that it is also not a caloric restriction, because the body itself is setting the intake.
Dr. Phinney has stated that his research subjects, in the initial phase of a well-formulated ketogenic diet, generally end up consuming somewhere in the neighborhood of 1500 calories a day, the rest of their energy needs being made up from stored fat. And as the excess fat is metabolized, of course, their daily caloric consumption increases until they reach the point of having no more fat that the body is willing to part with, and all their energy needs are met by diet alone. There is no need for calorie-counting at any stage of this process, as long as we continue eating to satiety.
It might also be worth mentioning some anecdotes in the other direction: Gary Taubes mentions in one of his books a research study involving a low-carb, high-fat diet, in which one of the subjects, while eating to satiety, consumed somewhere in the neighborhood of 3000 calories a day, and he lost just as much weight as the other subjects, whose caloric intake was far less.
And the British nutrition activist, Sam Feltham, recently performed an experiment on himself, in which he undertook to eat a 5000-calorie low-carb, high-fat diet every day for a month. All that happened was he gained a small amount of muscle and lost a small amount of fat (he was already lean), while his total weight decreased slightly. I read recently on these forums that he also performed the equivalent experiment, but eating a high-carb, low-fat diet, and gained quite a bit of weight, but I haven’t seen any post from him describing such an experiment.
All anecdotal, but suggestive.
Stay healthy, and keto on! 