The list of reasons for relocating LAX 25L a small number of inches to one side, at phenomenal cost, is a long one...perhaps longer than the offset from old location to new.
The A380 connection is tangential, at best. An airport improvement plan has been in the local political mill for nearly 20 years, with much heat and not vast amounts of visible light forthcoming. Soaring real estate values in the beach communities north and south of the airport have made noise levels a sore point, causing consideration of several plans to seriously redesign the airport. The 25L work is the only result, so far... and only a token from the airport-redesign point of view. Probably not much of a winner regarding noise, either.
Safety, strength, and the ever-present earthquake considerations of Southern Calif. geology, plus a great many years of changes since standards were current for the old rwy, plus some newly appreciated 'security' issues are collectively the main drivers. As for the offset... probably that is a convenient byproduct of reconstruction methods, as well as a token to improving separation between the L and R tracks.
One wag has observed that the only way to get a political decision on a contested issue in Los Angeles County is to include provision for pouring a whole lot of concrete somewhere.