I hadn't noticed it before, but nik_sharma is correct. Rev. Proc 2018-58 referenced by Notice 2020-23 includes in its list of actions with postponed deadlines the correction of excess deferrals (Section 8.19). So the deadline for the employer plan to make the correction is July 15, 2020, but still it may already too late for the employer plan to process such a distribution by the July 15 deadline.
