No, actually they’re not pre run in. I don’t want to start yet another debate about running in, but it never ceases to amaze me how this myth persists. I think it’s often peddled by sales folk who tell customers what they want to hear.
I’ve seen Porsche petrol engines being assembled at Zuffenhausen and the first time the engine is fired up is when the cars roll off the production line. They are run very little at the factory and are usually delivered with about 15 miles on the clock, so they are most certainly not run in.
You are right though to ‘settle all the components’ before stressing them. Note what Porsche advises in the manual.