imo it would solve a lot of fandom problems if people could hop on board with the idea that serialized media that was not fully planned from the outset can be interpreted as a unified whole AND can be interpreted as a developing trajectory.
in a show, each individual episode is (hopefully) a unified whole, in that events from the beginning function as deliberate foreshadowing for events at the end. the end is in conversation with the beginning because everybody involved knew what both beginning and end were going to be at all stages of development. if you choose to stop watching an episode part way through, your interpretation of the beginning of the episode will be objectively less correct than the interpretation of someone who saw the whole episode, because the beginning was created intentionally to be in conversation with the per-determined end.
within seasons of a show this is typically the case, such that episode 1 is foreshadowing what will happen in episode 15 (or whatever). the writers probably hope that, if you watch the full season and then rewatch it from the beginning, you will catch stuff they were doing to hint at where the story was going.
some shows' earlier seasons are also intentionally in conversation with later seasons that have already been planned. shows that have a sketched out 3- or 5-season arc are generally doing this. but a lot of shows don't function this way season to season — and especially a lot of them don't function this way across every season, even if they have some seasons that are written as pre-determined arcs.
in shows that do not have a full pre-planned narrative arc from beginning to end, the later seasons are in conversation with the earlier seasons, but the earlier seasons aren't necessarily in conversation with the later seasons because the people who wrote the earlier seasons didn't know where the story was going yet. they put information down that might get retrofitted to work as foreshadowing for what happens in later seasons (especially if the writing is good), but that information wasn't foreshadowing when it was originally written, because the end wasn't set yet.
so if you want to look back from the end of a show like that and read everything as foreshadowing that winds up working as foreshadowing, what you're doing is essentially noticing what the writers of the later seasons did: how they hooked the story they wanted to tell into the information that was already there. you can interpret it that way explicitly, or you can approach it by interpreting it as if everything had been planned from the beginning. these are interesting and often very rewarding ways to approach analysis.
also an interesting and often very rewarding way of approaching analysis is chunking the stuff that is known to have been pre-planned and interpreting that one way, and interpreting stuff that got built off of that stuff a different way. often this looks like cutting shows into sections; e.g., looking back from the end of season 1 to see how the beginning was in conversation with the end, then watching season 2 (if it was not planned when s1 was written) and seeing how season 2 puts itself in conversation with the beginning of s1, but not interpreting anything that happened at the beginning of s1 as being intentionally in conversation with events in s2.
using this latter framework, it is also fair game to analyze an earlier season without considering events from a later season at all, because the earlier season was not created to build to what happened in the later season. in a way this is ignoring canon, but it is not ignoring canon in the same way that ignoring the second half of an episode or a season is ignoring canon. you're not splitting something up that was written as a coherent whole from the start; you're splitting earlier parts of an evolving timeline off from things that the people who created that part of the timeline had no knowledge of yet — sort of like how with history you can analyze how events from the past built to the present, AND you can analyze events from the perspective of that past moment before the present had happened yet.
anyway yeah thanks for coming to my ted talk