Of course it is, because...that's literally the situation going on here.
"Abide by the player's rolls" IS a GM restriction. Period. End of discussion. If that's okay, then you cannot say that GM restrictions are inherently bad and untrustworthy. You must actually explain WHY they are bad and untrustworthy, in a given case. You can't just write them all off with a single blithe argument, as has been done in this thread.
No. The explicit argument was that ANY GM constraints are bad, period.
Sure they do. Just as with any TTRPG, the referee/MC/GM/whatever needs to agree that the fictional situation DOES match the trigger.
A player saying, "I look around" doesn't trigger Discern Realities. They have failed to meet the trigger condition. I fully agree that once it is established that that is the fictional context, the move fires, because "if you do it, you do it" and "you have to do it, to do it" combined make a biconditional. The former is the "if" part, the latter is the "only if" part: if the trigger condition is the state of the fiction, then the move definitely fires; and the move fires at no other time, only if the condition is met. But the text--explicitly and repeatedly--supports the GM asking for more input or expecting more than token action.
And, to turn your own words against you: This is a clever rhetorical maneuver. You have shorn off the context which makes clear that the GM is in fact part of the process of determining what the fictional situation is, and thus made it sound as though the PbtA GM is merely the slave of the players, bullied by their shouted declarations, unable to act in any way except to robotically execute moves.
Of course it is germane to it--because people have declared that ALL GM constraints, regardless of context, are unacceptable. But we know, for certain, without doubt whatsoever, that some GM constraints are accepted, even by those claiming that they're always bad. In other words, in order to reject some specific constraint or particular class of constraints, you cannot simply point out that they're constraints and call it a day. We must have an explanation for why this constraint, or class of constraints, is unacceptable.
I say "class of constraints" because I'm obviously not going to expect someone to argue against Discern Realities, and then separately against Spout Lore, and then separately against--you get the picture. I'm not saying every single possible restraint is a totally unique case that must be argued individually. What I am saying is that dismissing it SOLELY because it is a constraint isn't a valid argument. You need to explain what, about a given instance or category, is an actual problem, since some restrictions are acceptable and others are not.
And, just in case someone is feeling like ascribing an extremist position again despite complaining about others extremizing their own viewpoints: I am also NOT saying that all possible restrictions are presumptively good, either. I explicitly said so upthread when talking about limitations and creativity. Good restrictions can (but do not always) lead to creative solutions or workarounds. Bad restrictions simply hogtie you with no benefit, like my trivially-bad example of "DMing while blindfolded", or other trivally bad things like "only being able to adjudicate rulings while balanced on one foot and playing Old Lang Syne on a piano". Others may be bad for nontrivial reasons, which require more subtle analysis; for example, I would consider it a bad constraint for the game to require the DM to lie to the players, as in, they're explicitly not allowed to tell the truth to the players in a particular situation (say they're interacting with an illusion or something), regardless of what the players might do or not do. That's not of the same "trivially obviously bad" category, but I think we can agree that that kind of restriction would be detrimental either all the time, or so overwhelmingly so that it would not be worth the tiny chance of occasionally producing something beneficial.
As I have argued, it absolutely does meaningfully engage with that discussion, because it stakes out one end of the spectrum: We all agree that this is a good constraint, right? And it would seem you do.
And I, here and elsewhere, have argued that some constraints, we all agree are bad constraints.
Hence, if you're going to say that a particular constraint or class thereof is bad, you have to actually defend it. You can't just call out that it's a constraint and thus presumptively bad.