I've been playing since Day 1, and pretty much every day on this game.
I know for a fact, that S16 introduced more latency/lag into this game, and if I had to take an edcuated guess for S16, it was the introduction of DM.
Now, DM has more players on the map when compared to Arenas. More players, means more server bandwidth is needed to move that data, and it sure looked like for whatever servers EA introduced, it overloaded this game, and took away from other areas.
S16 was the worst for me in terms of lag, but S17, I am seeing still a lot of high ping matches.