A little clarification for the record.
Both USCIS and the Department of State have authority to grant citizenship in their specific capacities. In cases where a child born abroad is entitled to immediate US Citizenship, like this child would have been if his parent was already a citizen when they were born, it would be State processing the Consular Report of Birth Abroad, not USCIS. Then State would also grant and issue the US Passport for the child and Social Security would then do their part. USCIS would have nothing to do with this. These are all database records that don't get "lost".
In a case like this, both USCIS and State will be involved, and the records will be in databases that don't get lost. Those files will contain the child's birth certificate showing born before the parent was a US Citizen, and that an immigrant visa was granted and used to enter the USA. There will be a record of the first passport application as well.
If worried about "loss", make sure you don't lose the Certificate of Citizenship in the intervening decades between obtaining it and needing it, if ever.