Let's say you come to a raging river and want to cross it safely. A player that's able to add (or do something that adds) the existence of a nearby bridge across the river to the fiction would be authoring the removal of the obstacle.
While it's not quite as fitting for the genre of Blades, I could see something similar to the described Blades flashback mechanic being used to do exactly this. Player: I have a flashback of scouting this river for crossing a few days before we came to it. DM: you crit on your exploration roll to find a safe path across the river. It's an abandoned bridge that no one is watching just up the river from where you are.
So you've described almost exactly what would happen in Ironsworn using a
Gather Information check:
GATHER INFORMATION
When you search an area, ask questions, conduct an investigation, or follow a track, roll +wits. If you act within a community or ask questions of a person with whom you share a bond, add +1.
On a strong hit, you discover something helpful and specific. The path you must follow or action you must take to make progress is made clear. Envision what you learn (Ask the Oracle if unsure), and take +2 momentum.
On a weak hit, the information complicates your quest or introduces a new danger. Envision what you discover (Ask the Oracle if unsure), and take +1 momentum.
On a miss, your investigation unearths a dire threat or reveals an unwelcome truth that undermines your quest. Pay the Price.
The point here is again, the intent. The intent of playing Ironsworn isn't to just to "explore what's out there." It's to test and try your character, to see if your character is strong enough, resilient enough, and resourceful enough to fulfill his/her "Iron vows"---the things that drive your character forward.
On a strong hit, it would be entirely reasonable to "author" a bridge. On a weak hit, you might discover the bridge---but it's crumbling to dust in front of your very eyes and treacherous to cross.
Or there might be some other hazard associated with it --- you know, like a troll living underneath, nursery-rhyme style.
But again, the question is---what is driving the action? Is preventing the party from crossing the river
really all that important? What is at stake? Is it more important for the parties to move on from this river, so they can start engaging again with the stuff that's driving their character motivations and Iron vows?
If the answer is "yes," then move on! You've got your strong hit, the pathway (bridge over the river) becomes clear, and you move on to what's driving the character forward. You don't diddle around with, "Oh, well, there's not a bridge, and there's nowhere to ford the river here, so . . . . yeah, guess you're stuck?" Why make the player jump through more hoops just to get across the river?
It's about the intent and principles involved.