Your example is highly unlikely. Speaking of overall alone there are many factors that produce that future overall. The blue as the red is the actual and current overall. The red always goes up its the blue that trends in one direction after the first camp. The boom or bust is depending the volatility and higher the number, combined with the distance the red and s from the blue tells you how far the individual ratings will trend. (Mostly)
So, in theory, with a super low volatility, the future could possibly target a point or two different throughout the future camps in any specific rating. This is barely enough of a change to even see with defaults (or my weights much) but the small ups and downs are there.
Add some position changes ...like a 270 pound TE and guys will drop (with a bust) at first camp , then lose weight (pounds) trending to a higher overall. He might of lost a few points of carry or avoid fumble (with low volatility) but the 53 pounds of weight loss will add a few points of overall.
To me that guy will drop then go up but it’s just a display...no matter what it is the same player. But camps will produce slightly random results.Still, up goes up and down goes down...its it as simple as that. What I am describing is small observations