Successor Plan question

Deleted original question. Trying to condense something into a question that perhaps makes more sense.

Suppose I own Company A and Company B. Controlled group. Company A is the sponsoring employer, and Company B is signed on as a participating employer. Effective December 15th, 2018, I sell Company A - a stock sale. The new owner of Company A wants nothing to do with the plan, so does a resolution and amendment to terminate the plan effective 1/1/2019. Does not establish a new plan, nor are there plans to do so.

I still own company B. And, I've just purchased two more businesses.

If I attempt to establish a plan, other than a SEP or a SIMPLE-IRA, it would be considered a successor plan, right?

Now, the other question is whether, IF I establish a successor plan, if this "taints" distributions already made, or pending, to employees of Company A? It does not seem reasonable that it would.

Appreciate any thoughts. (And by the way, I have no idea WHY any of this took place - only know what DID take place, for whatever reasons.)