I am sole legatee in an estate with no children or spouse. The notary says he will send a copy of the holographic will to the court registry. Is that necessary?

Yes. When the will is handwritten and there is no protected heir (child or surviving spouse), the notary must draw up a report of opening and description. Within one month he must send it, with a copy of the will, to the court registry so that “any interested party may oppose it” (Civil Code, Article 1007).