Notice 2023-54 is the authoritative guidance. What the notice says is, "Final regulations regarding RMDs under § 401(a)(9) and related provisions will apply for calendar years beginning no earlier than 2024." The entire IRA industry has interpreted this as indicating that the IRS will not enforce the annual RMD requirement for beneficiaries under the 10-year rule until 2024. (Assuming that the final regulations with regard to this will be the same as the proposed rules, saying that this requirement in the final rules won't be enforced until 2024 implies that the rule won't be enforced in 2023.)
