The differences between the Triage and the Medivac were considered minimal. Triage was slightly faster due to lighter armor, with no missiles. The Medivac was said to have heavier armor, slightly slower and two small missile hardpoints. Both carried the upper turret as the only guns.
At concept, the two ships were otherwise identical in every other regard. We'll have to see what is actually presented next month.
Ben spoke of the battlecruiser as an item that has had considerable concept work done. I'd guess that Orgs with a Capital Ship construction bay on their Starbase will eventually be able to build it, since it was made clear that even the Bengal will be available that way. Beyond that, no clue. AstroHistorian has covered the ship in some of his video's, with what little has been said.
As the battlecruiser was stated to 'possibly be the last concept sale' CIG plans to do, we can expect to see a a lot of hype before it gets anywhere near player's hands.