It’s possible you didn’t have to do that form, my husband didn’t but for some reason my account couldn’t be verified.

And based on my understanding if your son isn’t able to purchase the bonds now because his account isn’t verified then he would not get the 9% interest. What I did is have my husband buy the bond for me as a gift and once my account is verified he will gift it to me (which hopefully is before the end of the year so it can count towards my 2022 limit).