In an unexpected move, PGI decided to increase ECM counter range of BAP to 360 meters while reducing the LRM damage from 1.1 to 1. If you're an LRM boat, this makes things really easy for you. You can comfortably sit at a range of 360 meters which is out of the range of brawlers and keep pounding the enemy without ever worrying about ECM.
At a time when a large portion of the community is discontent with LRMs, this is a very strange buff to LRM boats. The damage nerf of 9% is pretty much negligible if you consider that LRM boats bring in some cases thousands of missiles.
Though, this also coincides with AMS ammo buff. PGI buffed the ammo per ton for AMS to 2000 in order to match the Clan amount. 1000 ammo didn't usually last long in a match, prompting requests from the community for an AMS toggle. Now with 2000 ammo per ton it's not really necessary to shut it off, the ammo is plenty enough to last a whole round.
I realized the true intent of these changes last night in a match in Caustic Valley. I was in my support Kitfox with ECM and 3xAMS, covering my group from LRMs. The enemy was pretty LRM heavy and they had spotters/NARCers with BAP running around. Smartly, the enemy didn't engage in a counter-clockwise maneuver as usual, but retreated behind mountains with their snipers and LRM boats. We responded by fortifying ourselves in the Calderra.
I was the only ECM 'Mech in the team and because their BAP 'Mechs were always nearby, my ECM was disabled pretty much the whole time. Suddenly, that one ton of equipment wasn't be-all and end-all against missiles anymore. I had to rely on my 3xAMS to cover my teammates as they were targeted by missiles. When the long drawn-out battle ended in our favor, I had went through 6000 AMS rounds already. If I didn't bring 3xAMS with me, the match could have ended in a whole different manner. The AMS is "the" hard counter to organized LRM teams from now on.
TL;DR: The AMS is not a niche accesory beside ECM anymore. It is pretty much mandatory against organized LRM opponents from now on. Though, a single AMS can only do so much. The pugs have to collectively bring their AMS' to create an LRM "no-fly" zone.