There has not been break in oil used my auto manufacturers for maybe about as long as Ricky has been alive. Change like the manufacturer recommends and you'll do it every 5-9K miles. New or not doesn't matter any more either.
On a lighter note, I do agree somewhat. I'd change it every 3K (including the 1st one) with dino oil or longer with synth. I change my filter ever 5K and the oil every 10K. Works for me.
Anyone freaked out or laying awake at night because of my suggestion should change it as often as he feels it's needed.