You should probably go ahead and do the first change, just because it's a new engine and has never been changed. I don't know about the P-car engines, but in others you get small metallic debris that collects during the first few K miles that should be drained out. After that, change it just before the manual says to do it so you're not late (I think it's 20K for the 987) or annually if you don't reach the mileage.
One tip...make sure the engine is warmed up before changing it and get a sample for analysis so you can get an early warning if any parts start to wear.
