NO it's not true at all... And even if it were... if you wait that long to neuter him you'll end up developing other personality traits that could prove to be much worse.
He can be neutered as young as 4 months. And the younger his is the quicker the recovery time. I have 3 neutered males, (one neutered as an adult), and they're all perfectly wonderful dogs!
Early neutering will save you a lot of grief!