Eh, I don't know, what you say seems kinda stretched. Only a few sqaunt things (as you mention with it being "loose") suggests in Fort Mode that your the "top noble" or "collective wisdom of the government," it mostly frames it that your some sort of preternatural force guiding the Fortress. If all your dwarves die and only a child is left, is that really a "collective" wisdom of government? No, not really. Every embark starts with an expedition leader, but are *you* that character? No. When you play a character, that's Adv. Mode. The incoming embark arc of development when we'll finally get a more defined site theme to go by will be just that; scenario. It still doesn't mean your a specific character within Fort Mode.
And yes despite the exact "force" the player in Fort Mode is, it doesn't account for everything such as going missing or vampires- but even then when such things are discovered, the entire fort knows instantly while you ALSO know the new information instantly. Something I'd want is that info would be straggled from unit to unit as it goes down the network of general information to add to mechanical roleplay and watching it go around in a "stream" pattern, that'd be awesome. But for the player? No, not really.
Part of the fiat of Fort Mode is that your some near-omniscient (key word near) force that influences Dwarves behind the scenes and catches every interesting detail of what goes on the fort. Limiting fun little minutiae information in a simulationist game in DF makes no sense, at least for the mode we're talking about (Adv. is the inverse where you want to be immersed as possible in a SINGLE character).