People seem to be upset about splitting the community, so my suggestion is to offer the same game to Free to Play players, except don't give them any of the new weapons/equipment. They wouldn't be able to use the RPG and HMG, gain HP/Ammo from crates, and possibly limit all the existing ammo they have by half.
I fully expect this idea to get tons of flak from people who can't buy the game, but face it, your not gonna be able to get everything with this update. Either it's be split up and get nothing, or get nothing but still stick with the community.