New Holding Company to Become Plan Sponsor of Multiple Company Plans

Background:

This just got dropped on me this weekend.  Company A has a 401k plan, Company B has a 401k plan.  Both plans with same recordkeeper.  Ownership and plan features are identical for A and B as of 1/1/23, no issue with protected benefits.  Company C is being purchased, has no 401k plan, same ownership.  Holding Company D is being formed to own Companies A, B, C, and any future acquisitions.  All employees of all companies will be employees of Holding Company D as of 1/1/23.  My thought is to keep surviving Company A plan, merge Company B plan into Company A plan, have Holding Company D become the plan sponsor of Company A Plan and add all employees of Company C into the plan as of the closing date of the purchase.  I would file a final 5500 for Company B plan (though not terminate the plan) for 2023 (or 2024 if recordkeeper cannot merage assets as of 1/1/24).  Continue filing 5500s for Company A Plan (Holding Company as new plan sponsor).  On Holding Company 2023 5500 I would list Company A in Part 2 question 4, then on final 5500 for Company B list Holding Company A in Section 7, question 13c.  The timing is obviously tight, but am I missing anything in this strategy?

Thank you for any input!

Slight edit, All employees of all companies will become employees of the holding company as of 1/1/24, not 1/1/23.  Thanks.

I think that all sounds correct.

I think in 2024 is where you are going report the sponsor change from A -> D on the 5500.

Yes, that's correct.  Existing plan A will file on it's own for 2023, then the Holding Company D will file the subsequent 5500s.  Thank you for the clarification.