and I quote....
"To avoid new players from leaving the game, they understand that it's obviously better for trusts to be available in all 2.0 dungeons."
https://old.reddit.com/r/ffxiv/comme...w_with_yoship/
So Trust System is planned for 2.0 to 4.X content MSQ Dungeons to help players level through and progress in 2.0 to 4.X MSQ.
Now the question is...
Who will be the Companions we unlock for the 2.0 to 4.X Contents Lore wise and will some be "side-quests" Unlocks?
Considering the lore relativeness of Trust Companions for X.X point of the story I suspect there maybe some Lore thought into who we may get or can get.
Hope for "Hoary Boulder" and "Coultenet" as Trust Companions.
and maybe Unukalkai for players who complete the Warring Triad Storyline.