weird letter (not RFE) from USCIS about AOS and name

[perfect 39]

Son and daughter in law received appointment letter for January 8th at 12 noon for AOS interview.

Along with that received a second letter (not a yellow RFE, just a regular letter) asking for further evidence that original K1 beneficiary named Adriana (maiden last name) is the same person as Adriana (married last name).

With original AOS package was sent copy of visa, copy of marriage certificate (showing both maiden last name and married last name).

Any ideas on what they're looking for to prove original petitioner is same as the person now married and applying for AOS?

Never come across this before!!

Thanks

[KayDeeCee 4,893]

Is it just asking that the proof, which would be a copy of the marriage certificate, be brought to the appointment? Not sure why they would be asking for further proof. The marriage certificate is the legal name change document.