Lowly FO and others,
Rather than vent your frustrations here I suggest you go to a roadshow and express your dismay and concern or better still approach these VERY approachable people in one of our crew rooms and ask them directly.
Side letters etc are done for a reason. Previous management have had no problem adhering to letters of agreement, our new management have taken a while and pushed the point but they are now playing the game.
My strong advice, having been through this Eastern VS Sunstate BULL5HIT many times, is ignore the lies and exaggerations on this forum and get the correct facts from your negotiating team.
I am sure they will talk to you even if your not a union member!