I agree! I've posted about this myself. It could be as simple as the owner changed addresses and didn't notify the FAA. Then the Triennial Aircraft Registration Report could possibly be returned to the FAA with "no forwarding address", eventually resulting in "Certification Termination".
Insurance companies and salvage yards sometimes request airworthiness termination due to liability issues, without having to report any damage history (happens frequently during hurricane season). Such aircraft are sometimes sold as projects and can eventually reappear after being bought and rebuilt from salvage! I've learned of at least two similar incidents involving members of this forum, and know of a third involving a local owner.
Any prospective buyer needs to be aware of any possibilities, or any difficulty they may encounter in registration. I see "Cert Terminated" as a caution flag, but not necessarily as a red flag!