If you haven't paid for it you can do what you like, but it doesn't sound like a major issue in itself. The factory is probably assembly line where the person who tightened the brake hoses didn't fit the crank or the the headset. I would just voice my concern and get them to go over the bike and check every nut and bolt, which they probably have by now.

Take it as a heads up that bikes have problems, and use it as a reason to check your own bike regularly. Things like brake leaks, wheel clamps, seat alignment. I met a runner in a park once who stopped for a rest by a water fountain I was filling my bottle up at. We got chatting and he used to ride until one day (after bringing his bike back from a service) the front wheel fell out at speed, rare, but it can occur. He was in hospital for a week and it was many more before he could walk properly again.

I just bought a new bike a month ago and there is no way I would take it back to the bike shop even for it's first service. Bike mechanics isn't rocket science and I trust myself more than someone who's mind may well be off with the fairies.