Sure. Working out what makes for a good move - hard or soft - is a huge part of GMing Apocalypse World.Yeah, there's some fine points in terms of what is really within bounds. I mean, some tables will think that something like "Oh, you got an 8, there's a self-destruct device attached to the documents, you can try to disarm it..." is cool, and others might find that to smack too much of taking away what the player has earned. While moves are called 'hard' and 'soft', there's really kind of a range there. "A dog barks in the distance" might be considered fairly softer than the above self-destruct example. I'd say in this case the characterization is driven by whether the revealed fiction is in the way of achieving the ultimate aim, or simply indicating that some more obstacles might exist later down the road. In a sense though they're both pretty equivalent, either you disarm the trap or run away without your aim being achieved. Either you outrun the guard dogs or you're likely going to end up getting caught. Still, there's some difference. The simplest way to think of it might be that the more possible ways you can address an issue, the softer it is (IE disarming a trap probably has only one or two possible approaches, escaping dogs could happen many different ways).
Just as you're saying about D&D-style worldbuilding, so in this case: there is no unique solution dictated by the prior fiction. The GM has to make a decision. Sometimes they'll make better decisions than other times - everyone has their off days!
I'm sure you've participated in threads where various posters insist that railroading is just as possible/likely in "story now" play as it is in more "traditional" play. One thing that frustrates me about those threads is not only is that basic claim false - how would an AW GM railroad? what would that even mean, in the context of AW play? - but that it distracts from productive discussion about the actual pitfalls and challenges of GMing story now RPGs. The most obvious one is coming up with consequences, be that in the AW soft/hard move framework, or the Burning Wheel framework, or whatever else is required by the particular game being played.