I haven't seen the system in full use yet but I think 1 will attract a new player base which is what Dice needs.
Besides identification issue as to who is on what side, I had no problem with the specialist setup. I like the flexibility.
As to this constant complaint of specialist not promoting teamwork, the old class systems never really promoted team work. Take BFV. Biggest complaint was everyone was running the Medic class, yet no one is raising players or throwing pack. First complaint I read when I came back to BFV. Sniper/Recon class BF4/3? Everyone was always complaining they were on some far hillside not doing anything to play the objective. Support Class for 3/4/V? No one was ever throwing ammo boxes. In fact for BFV, they made so you could run by a player to get your ammo because of the complaint that ammo wasn't being thrown.
In the beta, Battlefield played like it always does. 3/4 of the matches where lopsided when one side dominating most of the match, some matches were close matches with both sides down to a few tickets and the rest a little more balanced. No different than any other version of Battlefield that I have played since Bad Company 2.
In the beta, players want to do their thing, they did. When they felt like working together, a tank didn't last 5 seconds. Classes never really did much to promote teamwork for Battlefield. It's a sandbox where players played how they want to play. Abuse the classes the best you can to play the way you want to play.