Sidney Powell is going to file a suit in Georgia that she says will be Biblical. She's likely to accuse the governor of accepting a bribe from Dominion to install their voting machines. The statement was probably issued to make it clear that it's not Trump or the campaign making the allegation.
Creating this drama makes sure that everybody will have heard about the distancing of Powell from the Trump team, and will make it very hard for anyone to claim that the accusation is coming from Trump.