The constitution say who is a citizen of the US. If one is going to make a citizenship determination under US law, the constitution is one source of law, but not the only source of law. There are literally thousands of cases in US law on the subject of citizenship, when citizenship is in question. The determination of citizenship in those cases looks to citizenship law of other nations.
Your error, and you are hidebound to it, is to believe that as a matter of law, naturalization requires participation in a naturalization ceremony.
Sorry, you are wrong again
The Constitution delegates that authority to Congress. I have NEVER said that naturalization requires participation in a naturalization ceremony so please stop trying to put words in my mouth. What I have said is what the Constitution says, specifically that Article I Section 8 enumerates the authority of Congress to establish ALL laws with regards to naturalization. That includes who is a citizen at birth and does not need to be naturalized.