There really is no way to make this a team-based game unless you build the concept around a team-based system and reward team contribution rather than individual performance. Of course, this won’t be doing that; there will be K/D ratios and Battlefield won’t be nearly as team based as it could be, because the concept is that they “encourage but don’t force team based gameplay” which in itself… eliminates team based gameplay.
Unless there is a larger goal than just individual matches (Like Planetside 2 and Warhammer 40k: Eternal Crusade, where the goal is to gain control of the planet or planets) and the EXP system rewards team contribution rather than individual performance, Battlefield will always be just a lobby shooter that politely encourages squad gameplay.