I just finished writing an article about what I consider to be the best splits. I personally do not use bro splits, or rarely.
Can they be effective? Absolutely! I just don’t find them to be checking all the boxes. I respect Paul and he is certainly a great coach and athlete. But we do things differently and that’s fine.
As for the research, Schoenfeld is awesome but in the past he had several studies that would actually contradict each other. So I would need more than that to make me change my mind. I would also need to read the details of the study. Subjects, lifestyle, how the training was implemented etc.