It depends on wen the distribution was required to be made. If the RMD was due was due in 2023, then that would would have been during (in) the correction window. If it was a RMD due in 2024, it would not be during the correction window since it was a timely made distribution. If the RMD was due prior to 2023 then the new rules regarding the correction window would not apply. According to the IRS:
If an account owner fails to withdraw the full amount of the RMD by the due date, the owner is subject to an excise tax equal to 25% of the amount not withdrawn for 2023 and later years. The SECURE 2.0 Act dropped the excise tax rate from 50% for distributions required for 2023 and reduces the tax rate to 10% if the error is corrected within two years.