Keto is the absolute worst you can do as an athlete since carbohydrates are required for fast recovery. No professional athlete would be on keto while training. The idea that an athlete should have even slightly over 1g/kg of protein intake per day is correct. However, over 2g/kg/day poses a risk of permanent kidney damage.

Moreover, losing 4 kgs or more of fat in a month increases the risk for cardiovascular disease: the blood cholesterol levels of the subjects may rise to unhealthy levels. Some are resistant to high cholesterol, but statistically it's a risk.