I have no professional experience with this, but if it's the school that's pushing for advancement I would consider it. I think it can be difficult for elementary teachers to differentiate instruction, and it may depend on the luck of the draw with a motivated teacher.
I do think it's beneficial that he's on the older side for a kindergartener - so it's not like he'll be miles behind other kids in age or socially. I assume your district has a Fall cutoff for kids turning 5 for kindergarten, so I assume he'll be the youngest in the class, but potentially only by a few months. My child has a late summer birthday, so she's almost a year younger than some of her classmates already, and so I'd hesitate to advance her if that was an option just from a social perspective.
Good luck!