That’s certainly the myth, oft repeated by medical “ professionals” who repeat bad science like gospel.
But for lifters and knowledgeable sports med doctors, they know that If you are properly hydrated, take creatine with carbs, the water goes into muscle cells which expands, making you much stronger. There is zero effect on kidneys.
Not exactly “bloating” as traditionally thought.
Years ago I pumped up with over hydration and creatine. I got impressive results. I was gulping close to a gallon a day. Once you stop, the water leaves the muscles and size returns to normal.