Having been around & handled hundreds of youngsters, I think it depends on the colt. We've had some very studdish weanlings and then had others who never acted like a stud up to a mature age even left intact. I do agree that colts tend to be more prehensile and mischievous in general than fillies.
My 9 month old colt (will be cut in a few months) hasn't shown any stud like behavior yet. Woodstock was cut as a 4 yo after injury, was an aggressive rank mess when I bought him, but even with being cut late he is a perfect gentleman now. Though I attribute that more to very consistent training & being put in his place by my bossy mares than the actual loss of parts lol!
Life is like a camera. Focus on what's important, Capture the good times, Develop from the negatives and if things don't work out, Take another shot.