It is indeed right that LH changed its policy on mobile phone usage! It used to be not allowed at all onboard the aircraft to use your mobile phone!
Now it is possible to use your cell phone onboard until the doors have been closed on departure or after the doors have been opened after arrival at the gate!
So doŽnt stress out over this since this is still much more restrictive than most of the US airlines. It also is true that cell phones do work in the air, but the signal usually fades out when you climb through 6,000 - 8,000 feet (at least in Germany)! For phone service in the air we do provide a few satellite phones in the aircraft of our longhaul fleet!
Happy calling.....
a LH 340driver