khn, assuming your description of the deal agreement, your client might not know what set or series of retirement plan transactions would satisfy the business deal until there is communication involving (at least) the seller and the buyer, perhaps each plan’s administrator (if either plan’s administrator is distinct from, respectively, the seller or the buyer), and maybe each’s lawyers and accountants.
For example, a spin-off, even if otherwise a nice idea, might be a nonstarter if the acquirer’s plan won’t accept it.
If the deal teams didn’t communicate about these points more fully and sooner, that’s disappointing. Deal work often happens that way. Even if it’s now only days until a closing, your client might want to surface some remaining retirement plan questions.