Cereal at 8 weeks

Okay so basically I exclusively breastfeed and a pediatrician said that if I want my 8 week old to sleep longer stretches I should give him cereal at night. But I think he sleeps fine and I haven’t complained about it so why would my sons pediatrician recommend that? Also I don’t know much about anything because I’m a FTM but I’ve heard that doing that will reduce your milk supply. My husband says we should consider doing it and I don’t want to but I want to make an informed decision. What are the pros and cons?

Also I should mention that he’s not underweight or sleep deprived