I've been a lucid dreamer for nearly a decade, so I always go into these articles with a bit of caution, but not a bad post here. From my experiences, I think dreams are kind of all of the above; memory/recent events, random/active imagining and making abatract connections, and of course some symbolic representative things that can be obvious or not that relate to something in our unconscious. I always saw the subconscious as more of the mediator between conscious and unconscious minds, so all the long term really heavy shit that is revealing about the self is likely there. The subconscious is more of a clerk on the phone with the conscious mind and digging in a file cabinet of the unconscious to see how everything fits and connects within. From a lucid dreamer's perspective, at least.