From the email that we got for oath:Hello Guys, I am sharing my experience regarding minor oath invitation and ceremony attendance.
I applied for me and my son (minor-12years) together as family via paper application. I received my oath invitation email last week on 3rd Aug and oath was scheduled for 10th Aug (Today). I did not received oath invitation for my son with me and I assumed that he doesn't need to receive oath invitation because I mentioned in application form that he will not attend ceremony. Today morning, I have attended my oath ceremony. During registration process, once my registration/verification/PR card cutting was done, I asked IRCC official about my son's registration/verification. She checked in to system and tried to confirm with clerk but she did not get response. After that she said my son is not scheduled for oath with me so she can not register him and I can not cut his PR card but she will try to get response from clerk during ceremony and will let me know if there is some confusion. But ceremony was over and she did not get back to me. Now its my headache to get my son's ceremony done. I am not sure if anyone had same experience before but is weird that minor did not receive oath invitation with parent. Just a heads up guys, if you come across same issue, please act in advance before your oath and confirm with IRCC about minor's missing invitation.
"A person aged fourteen (14) or older who is granted Canadian citizenship must take the Oath of Citizenship to become a Canadian citizen. Children under 14 years of age are welcome but not required to take the oath. A minor child must be accompanied by the parent/guardian who submitted/signed the application on their behalf."
My son was present and the agent verified both his PR card and his provincial health card and asked to cut his PR. After that the clerk said that it was not necessary for him to stay for the oath but that's optional.
I believe that they want to make sure that your child is physically present in Canada for the oath. You can send an email to IRCC to inquire for next steps for your child.