Successor Rule if Profit Sharing Doesn't Have a 401(k)?

Our client had a cash balance and profit sharing plan effective 2015. There was no 401(k) component, it was all employer money.

In 2020, they had an offer and thought they had sold their business, so they terminated their plans effective 12/31/2020 and assets were distributed. The deal fell through, and they'd like to put in a new CB and PS plan as of 1/1/2021.  Their payroll company is saying they can't do the PS plan, because they need to wait a year due to the successor rule. Is this true, if there was no 401(k) in the original plan?

Thanks - 

Sue

The successor rule applies to 401(k) Plans. Their payroll company is confused.