No evidence of that. In fact, Goku's statement suggests the opposite. There would be absolutely no need for Goku to say he might be stronger or is probably stronger if he was referring to SSJ Broly because that wasn't the limit of Broly's power and Goku knows that considering he fought him as Gogeta. SSJ FP Broly would be way beyond Beerus if that was the case and Goku's statement does not in anyway suggest that. And from what I've heard, Goku refers to Broly as he is now he'd probably be stronger than Beerus, which means he's certainly not referring to SSJ Broly. And this is all on the basis of this nonsensical "No being in existence could beat Broly as he was" statement in the first place.