If its anything like Frostbite 2, it will dynamically use more vram if its available to preload textures, terrain and increase LoD so objects appear more detailed further out. So take the vram usage with a grain, if you have less vram it will turn that feature off, the game will run fine but wont look as good into the far distance.
Edit: all the usage of deferred MSAA shows is that devs are too damn lazy and throw in a crippling feature for minimal visual IQ gains. they could have taken the dx11 approach of doing Forward+ via compute and have functional MSAA without the performance hit for the rest of the game visuals. its sad that even today games come out with either no AA, or blurfest FXAA.. I guess at least DICE is kind enough to include "barely working" deferred MSAA. One of the most inefficient methods ever at removing aliasing, does a bad job, sucks a huge amount of performance.