I am really not following what your point even is anymore, let alone how these quoted bits relate to it.
This reply is also relevant to
@EzekielRaiden,
@Micah Sweet and
@Bedrockgames.
Consider a typical CoC module like The Vanishing Conjurer, which I quoted from upthread.
The way that someone would
literally discover the solution to the mystery is be reading the module. But that wouldn't be playing a RPG.
The way that a player, in a RPG, discovers the solution to the mystery is by saying things - ie saying what it is that their PC does (
declaring actions) - which then prompt the GM to say things - that is, saying what happens next, or saying what the PC notices, and the like (
stating consequences of actions). The GM says some other stuff, too, like describing the circumstances in which the PCs find themselves (
framing scenes).
The GM, in saying the stuff that they say, treats what is written in the module as a constraint. It constrains both in telling them what to say, and telling them what must govern any extrapolation.
One reason for picking this scenario as an example is that the whole thing could be played freeform - even the SAN checks are very modest (eg 1d4 SAN for seeing the ghost of Leclair). That is to say, there are basically no
mechanical constraints governing what anyone says. The constraints all follow from either
what is written down about the fiction, or
what is subsequently established about the fiction.
To the extent that this is "real" or "objective", therefore, it's about the existence of these constraints on what is said - especially the constraints on the GM. What the Gm says is not simply chosen by the GM, relatively unconstrained, on the spur of the moment.
My point is that there are other ways to generate constraints, which will also then shape and limit what it is that participants say, beyond
adherence to pre-authored material. And the RPGs I've pointed to set out these constraints. Tautologically, when RPGing this way the players to do not identify what it is that the GM (or module writer) authored prior to play. But that does not mean that the players are simply
portraying the solving of a mystery (as would be the case if they were actors in a scripted play), or that they are deluding themselves into "solving" a mystery whose solution they are collectively authoring (the dreaded "writers' room").
Just like the players of the Vanishing Conjurer, the players can have their PCs pursue leads, form suspicions and act on them, etc. And the rules of the game generate consequences for those action declarations that are not simply
chosen by the participants. Outcomes can be generated although no one would even have wanted them had they been free to choose!