Does the majority of the 'power' of these finetunes lay in the dataset? So once GPT4 finetuning is out (this fall), could they in theory just use the exact same

Does the majority of the 'power' of these finetunes lay in the dataset? So once GPT4 finetuning is out (this fall), could they in theory just use the exact same datasets for GPT4 finetune?