I dont totally agree with your statement. The reason around 3-4 litres of water should be drank per day by people training and on high protein diets is because of uric acid build up from higher protein diets. This can cause gout and kidney stones if not flushed correctly.
I'm not sure what you call a "high protein diet". I have never advocated more than 1.2-2.0g protein per kg bodyweight daily, and that only for those intending to
build muscle. For a typical 65kg woman or 80kg man, this is around 90-160g protein daily. For those intending to
maintain muscle mass, 0.8-1.2g/kg is sufficient; 50-100g daily.
I know of no studies showing that this level of protein consumption leads to gout or kidney stones, or whether higher consumption of water offsets this. If you do, please direct us to these studies.
I cannot answer for people who choose to consume 250+g of protein daily, anymore than I can answer for people who drink a slab of beer a day.
All I can say is that if people have their protein consumption at the 1.2-2g/kg level while bulking, and the 0.8-1.2g/kg level while maintaining or cutting, and if they have lots of fresh fruit and vegies, nuts and beans, and some meat, fish and dairy, along with their starchy foods, well there's no need to be sculling back gallons of water daily.
In fact, gout and kidney stones are not commonly found in otherwise fit and healthy individuals. They're commonly associated with obesity, high blood pressure, adult onset diabetes, and a nutrient-poor diet. That is, people who eat heaps of meaty fast food and little or no fresh fruit and vegies, consume little fibre, and who are basically sedentary.
Gout and kidney stones really are the least of the problems of the obese, malnourished, unfit, weak and inflexible person.
In any case, a person's hunger and thirst adjust to their needs. If you lift heavy you will get hungrier. In the summer heat your appetite is lower, but your thirst is greater. And so on. So if your kidneys need more water, the thirst signal will kick in. You can choose to ignore that thirst - just as people ignore back pain, gasping for breath when running to the train, constipation from not eating enough fibre, and so on - but it will come.
The only time the thirst signal fails is in cases of hyperthermia. This is unlikely to occur in the lives of most people just doing their day-to-day jobs and working out a few times a week. And it's certainly not something that'll happen daily for years.
Drink when you're thirsty, and/or if your urination is acidic and painful. You can drink
more than that and (short of drinking 10+lt daily) it won't do you any harm, but nor will it do you any good.