It seems to me that #2 is just moving when the encounter is.
Say I have 3 directions and I want the PCs to potentially visit all three, but the one they need is always in the 3rd location.
If they're given nothing distinguishing the 3 directions, then there's no real reason why I can't have the 3 locations appear in the order I want - I've given nothing much for the PCs to make a decision with anyway. (They chose a direction not an encounter).
So that is the point.
There
is something distinguishing those 3 directions in the consistent reality model; which direction has each encounter.
When the players are given a choice, that is when the 3 different possible encounters should be "placed" conceptually. Then, because now the 3 directions are different, the DM can and should describe them differently, before the encounter is reached.
If the first path chosen leads to A, second to B and third to C, nothing the DM says before the encounter is "placed" can matter. The DM must keep things vague enoigh that they can move A/B/C around, which forces A/B/C to be disconnected from the details of the world
and the world to be disconnected from them.
If instead you have a bag of encounters, these can be contingent on the world situation. Picking the swamp path leads to some swampy encounter, the forest path to a forest encounter, etc. The DM's structure and tools lead to a different kind of experience for the player; not out of necessity (as noted, the encounters and description could match exactly), but out of efficiency and laziness.
With bags of encounters which have "keywords" or whatever organizational system attached, this means DMs are now wanting to drop keywords on players at decision points, to hang their bags of encounters on.
In theory a DM could do all this and guarantee A/B/C order while improvising the world connections (the kind of drsgon in encounter C is substituted out based on terrain, but is always the 3rd path). But
lazy.