I hope Square doesn't keep deeming certain content unnecessary

[Daeriion_Aeradiir]

Your Hildibrand lore excuse is funny, considering he literally shows up in the 5.3 dungeon.

To be fair, he showed up there in a lore compliant manner, within the context of what was happening at that exact point in the story that would make zero sense out of that small window of time. There's only one current path that non-WoL people can reach the first, and you'd have to do some extreme handwaving to explain why the Exarch summoned Hildibrand, let alone even knew who he was. That's also for just Hildibrand; it'd be an even gianter stretch if you wanted to bring in the usual cast of Hildibrand characters like Godbert.

But lore aside, they already explained why they canned him for SHB: He was getting stale. Which I agree with. i'd rather they remove him for an expansion and come back with a great, well thought out and funny storyline than try and shoe-horn him in just for the sake of it. HW's Hildi plot already felt forced as is (which it was, since Scholastic was meant to replace it but fans cried out for more Hildi so they had to bring him back and rapidly write a shoe-horned story), I'd rather not see a repeat of that.

As far as squadrons, you fail to see one of the biggest points of why they developed trusts instead of expanding on squadrons:

trusts cost no investment from player time in order to use them for their intended purpose.

trusts are auto-leveled to dungeon levels while you're in the middle of the MSQ, meaning they're always an available option in order to help complete the MSQ if queues are taking too long, which yoshi-P described as one of their intended purposes before SHB launched. Even post SHB, they're auto-leveled to 80 during your first run of any of the level-capped MSQ dungeons so you can't ever get railroaded by a dungeon.

Contrast squadrons, which to theoretically use them in level 70+ dungeons would require:
-Hitting max ARR rank of your grand company
-RNG recruiting one more off of challenge log entries which reset weekly to allow them to be used in command missions
-manually leveling them up all the way to 70.

It's not really surprising why they focused on trusts. They're malleable in terms of design & usage, mandatorily forced on you as part of the MSQ so you can't avoid unlocking them compared to squadrons being fully optional, have much more character identity and make more sense being with the WoL than random squad peeps due to being heavily involved in the MSQ. Not to mention even if they brought squadrons to the first, you'd have to explain why these 'shard' selves feel compelled to align & fight with you when they haven't met you ever, or why they somehow have the exact same stats, gear, experience, etc as their source selves.