First those are horrible definitions of the types of adventures they are describing and it is a horrible definition of an encounter. WOTC generally hasn't been good at this sort of thing IMO (it is one of the reasons I was going back to the 1E DMG in the 2000s). But I would add, an encounter is not, in my mind, a scene. An encounter is simply any interaction that occurs during play with an NPC, monster or being. Being that, encounters can have more or less definition. This is why I was asking whether you felt all encounters meant the GM was acting as storyteller or planned encounters. But that said, throwing a group of orcs at a party is not the GM acting as storyteller in my opinion
How did we go from “5e is the dominant force in the market currently so we should assume their definitions” to “well but actually we can’t use their definitions and framing for things because [reasons].”
Edit: just to be clear, when you say “encounter” to me as somebody who came up from the 5e world - you mean “pre-planned encounter via map and key or notes that has some sort of plot relevance or danger” or “random encounter rolled off a table.” Visiting a merchant is not an encounter for me, talking to random townsfolk is not an encounter, meeting the Guard Captain to get a Plot Cookie might be an encounter but probably not.