Just to be the devil's advocate, the Forgelite engine used in PlanetSide2 can calculate shadows for huge numbers of lights, but it's a new and very streamlined engine made by a huge team (Sony).

Major? Downgrade this to minor and I'd vote for it. Dynamic shadows from lights is VERY resource intensive and a huge addition for the game, if BIS has done this and plans to introduce it later on, good on them, if not I see no "major" problem.