No, that’s definitely not the case. I would not be naturalized when my parents were. There is an established legal process. I could be 30 years old when they got naturalized.
One grandfather had 12 kids without being naturalized nor his wife.
My post that you responded to was a description of how simple the citizenship question could be. If a couple comes here legally with children, then all would be naturalized at the same time. The same for any children born after arrival but before the parents are naturalized.
Apparently there was some substantial delay in your parents or grandfather becoming naturalized. You don’t say why this happened, but if this nation would simplify its laws and enforce its laws, such situations probably would not exist in the future.