None of this is true. Alien numbers are issued to green card holders (lawful permanent residents or LPRs for short) and many non-LPRs such as illegal non-citizens that are deported or DACA recipients. Next, the A number is still relevant even after naturalization because it is a unique identifier for immigration records. It is the immigration equivalent of an SSN. The naturalized citizen would still need this if, for example, they wanted to petition for a relative or if they needed a copy of their immigration documents for whatever reason, like they lost their original naturalization certificate. Lastly, the naturalization certificate is NOT surrendered upon application for a US passport and is supposed to be returned to you like any other original documents, such as a birth certificate, sent in with a passport application. And even if it were to be destroyed, you can still obtain a replacement certificate by filing an N-565. It is not surrendered unless the subject is denaturalized or they renounce their US citizenship.