This is why I’ve decided to follow an OMAD (One Meal a Day) diet, if I have to dirty up my mouth to survive, I’ll at least do it one time a day.
Take these anecdotes with a grain of salt.
Assuming you're not predisposed to other issues and that you still brush your teeth at least once a day most of the time, that's the speed of decay you should expect and the timelines you're working with. The daily, monthly or even yearly progression is miniscule, making it difficult to observe if it has been slowed or halted, especially in messy anecdotal tests.
The exception being tooth grinding, which can go faster and is easy to measure.
I can wake up and go for a 15 mile hike with no breakfast and not feeling hungry.
Breakfast is the least natural meal, you should not even be hungry when you wake up, it's unhealthy and should be skipped.
The only broad concern I would have is being more prone to accidentally having too much calorie restriction for a prolonged period, where metabolism reduction, potential thyroid issues, and potential nutrient deficiencies can come into play based on highly individual thresholds.
I also suppose some people who fast, especially on very low carb/carnivore diets can sometimes experience the exact opposite of your concern, their blood sugar levels can become constantly elevated, seemingly induced primarily by elevated cortisol, though also seemingly effected by other complicated individual factors like the kinds of stored fatty acids they are burning.
Aside: My wife recently had a kid and the experience taught me how much work gets done to you just because you're being monitored that you may not actually need. You definitely need to know your own body and trust yourself to some degree. At least pregnancy is having a resurgence in "natural" birth.
Is dentistry the same? I could see this as plausible. My assumption at times has been that people's teeth all just fell out immediately before the 1900s lol, which is probably further from the truth
I added this to how I was able to have a full hole in my tooth fill back (when poor and in college) in by just keeping it clean, not eating junk food, and swishing spit in my mouth around that tooth religiously for a long time.
Dentist later said, "nope, didn't happen, teeth don't work that way"