It seems like Legacy year 1 is over at wave 3, at least in terms of new characters (there may be repacks or solid case sent to retailers). Any new reveals, including Breakdown are for the year 2 of Legacy which is subtitled Evolution.
First they revealed the Poster for Legacy Year 2 where you can see a lot of the line. It gives us out first look at Armada Prime, which will most probably be the Commander Class figure, along with lots of core class Dinobots and deluxe Junkions, which are this line's gimmick. Aside from some of those and deluxe Bombshell and Crosscut, the rest on the poster did get revealed:
Core class
Slug
Sludge: There will be 6 core class dinobots and they combine into Volcanicus
Soundblaster
Deluxe
Breakdown: comes out in Legacy Evolution but will have first year Legacy box
Scraphook: new junkions that can break apart and combine with other junkions or other characters like weaponizers.
Armada Hot Shot
Needlenoze with 2 targetmasters that transform and combine into a bigger weapon
Voyager
Leo Prime: very realistic animal take, not cartoon-like
Tarn: many 5 mm ports for all sorts of loadout options
