I don't think this is true at all. In Florida, notaries are appointed by the Governor, an elected official. Nevertheless, notarizations are "records" within the meaning of the FFC clause. In Louisiana, notaries keep books of their notarizations. More importantly, the incapacity of a notary will not invalidate the notarization. The fact is, notarization is a historical artifact and is essentially meaningless. Keep in mind that tax returns do not need to be notarized and you can still be prosecuted for perjury if you lie. Need a quick notarization with no notary around? Look at 28 USC 1746: type the language given there on your document, sign and you are good to go for everything except real estate transaction.
However, notarization services are not public acts, records, or judicial proceedings. (Strictly speaking, notarization is a public act for state law purposes, but not for federal law purposes.)
EDIT: To clarify, a "public act" for federal law purposes is an act by a publicly elected, or appointed, official of the state. Local officials (county, city, etc.) do not have the power/authority of "public acts" for purposes of federal law. A notary is a state-level bureaucrat, but is not an "official" for federal law purposes because they are not elected or appointed--anyone can be a notary if they pass a simple test. EDIT 2: Note also that Congress gets to say when the FFAC applies, and they have chosen not to apply it to notarization services.