It’s my understanding that diet breaks can aid in fat loss-- not sure whether it actually does something beneficial metabolically or just helps with adherence. I wonder if taking a break during a bulk might be beneficial by way of helping reduce the amount of fat gained while bulking. Is there anything to suggest that it might? Furthermore, would you expect there to be any significant negative impact to a bulk period if a person decided to go down to maintenance calories for about a week before returning to bulking?
If adherence declines during a dietary intervention, yes, a break may help some individuals - though this is far from universal and is related to adherence, not any physiological process regarding body composition.
As far as reducing the amount of fat gained using a break, I cannot make a rational or empirical argument for that so I’m not sure it’s really something I’d advise. I don’t think anything will be different with a 1-week change in energy intake.