He would tell you that.
It's how they're trained.
Professional racers, engine-builders, etc recommend you do the first oil change early.
This is to clean out off the fine metal particles collected while the rings seat themselves. After that, you can change your oil according to the Oil Life Monitor, like the dealer said -- and you'll be fine.
Sooch is right -- it won't hurt ANYTHING to change it early. (except maybe your wallet)