Making this post as a potential satisfaction for those who would want a potentially definitive timeline. (I know the bologna episode exists but we're just gonna say this is either it's own branch of the multiverse or it gets fixed offscreen).
For those who haven't read the comics (or at least those who forgot about them), there exists the "Zimvoid arc". This is the IZ version of the multiverse, the bypass for odd episode logic or weird timeline inconsistencies.
Because of the multiverse's existence in the comics, this would theoretically make all IZ media canon. Offical and fanmade (no i didn't make a typo).
By this logic, this would essentially make scrapped media/plotlines canon. Such as the original series pitch lore, or even the pilot. (For those who believe potential references to JTHM as true, Nny would potentially exist in one of IZ's timelines as seen in his own comics, aka JHTM is a Zimvoid timeline).
Considering this concept, the pilot is canon. I bring this point up for another theory.
The Pilot is the Zimvoid timeline. Aka: Pilot Dib is Zib.
There's multiple ideas that lead me to this conclusion.
The pilot version of Dib, as you reading this or myself might think, has a creepiness and edge that he is not shown with like this past the pilot. I'd like to think there is a lore reason for that, which to me is canon to this timeline.
The series pitch booklet/pre-pilot concept told Dib off as more of the creepy kid seen in the pilot. I'd like to believe this version of Dib as a result of the lack of care/involvement in his life from Professor Membrane and those around him, which ETF makes a big point on (also the booklet points this out, so it would be more likely than not a canon lore bit).
Even Zim became uneasy with him at two points in the pilot. 1: When the robo-armor begins to malfunction, the scene cuts to Zim inside the suit, squealing in fear or stress.
2. As Dib makes the big blow (either the shot of him aiming the food launcher towards the screen or the final blow), the screen shows Zim's eyes inside the suit, the pupils of his lenses(?) shrinking (This is one of multiple visual tactics animators use to convey fear).
Zim being Zim has no normal reason to be scared of Dib, even when close to failing a battle.
Why would he be scared of Dib if he didn't think of Dib defeating and/or exposing him to be likely at all?
Because Pilot Timeline Dib was more likely than the series-to-movie counterpart of himself to fulfill his goal.
With this logic, Pilot Dib defeated his Zim at some point, and (given the portrayal of him), ended up mentally breaking to a point where the potential of the Zimvoid arc grows.
By the end of the day, Pilot Dib eventually becomes Zib.
(You might be wondering why both versions of Dib are so mentally different. Well, given the apparent loss of everything Zib has experienced, this could've been the last straw before Pilot Dib gave up)
Regardless, onto the post-pilot media!
The comics, as i'd like to believe, are the day-to-day things in Zim and Dib's lives. The "meanwhile" after an episode ends.
The series is usually at a peak with the intensity of situations. There have to be times where neither of the two are dealing with something big like the florpus or a "10 minutes to Doom" situation. Shows like TADC, for example, have certain episodes that are filler to the plot, but are acceptable when it comes to logically having more casual days, even if having it onscreen isn't necessary.
The comics would fill these spots for the most part. I know that the first part of the comics lines up with the movie, but i'd say the rest of the comics are the in-between content. The first issue is in a weird spot.
Then comes the Zimvoid arc of the comics, most likely imo before the cancelled episodes "The Trial" and "Mopiness of Doom".
The Zimvoid arc is only there because of how I see the trickster connection Z and D make in the movie (the friendship bracelet buildup. I really only see that bit of the movie being canon if they had some kind of crap happen beforehand.
Then comes the previously mentioned cancelled episodes.
"The Trial" has the fact come to the screen that the Armada/Entirety of the Irken race despises Zim, including the Tallests. I feel that the fact would get to Zim at some point, even if the episode's script ended with Zim's oblivious determination (Could've been a draft script idk)
Then come the events of Mopiness.
This episode has Dib questioning his efforts in paranormal pursuit. As Dib tries moving past Zim, Zim becomes mopey (hence the title). In my view, this is Zim's backhanded and complex care about Dib (not like the ship sorry). Zim has no reason to leave his residence if Dib doesn't care. It's pointless to scare anyone or battle anyone who doesn't care, hence this mood swing. None of the other skool kids care, not even Gaz (for the most part)
Some point during this time, whether it's during Dib's decision making or as he returns to the "house", Zim is formulating a huge, last-effort plan to regain the trust and pride of Tallests Red and Purple (as y'all refer to them idk if they have confirmed names), and almost at his breaking point.
(This is where the theory becomes a bit iffy, given the implications of the episode's script being finalized, but idk)
As Dib arrives at the house, returning to his focus on exposing Zim, Zim is oddly quiet. Not even a peep.
This is part of the plan.
Zim knows how Dib thinks. Dib always believes he up to something, especially when keeping quiet. Given the supposed timeskip in ETF, Dib likely would have thought Zim was planning serious shit.
This leads to Dib's state of isolation seen at the beginning of ETF, where the rest of the timeline plays out as seen.
You might be questioning the lack of presence of other kids besides Dib and Gaz (And the one gag with Poonchy and Minimoose), or even Ms. Bitters.
The movie takes place during the summer, given how none of the cast is in the skool.
Besides being irrelevant to the plot, Keef, Poonchy, Torque, etc, they're probably at home or out somewhere else for summer activities. This would include Ms. Bitters, even if she isn't exactly imaginable outside skool.
(I know this is long as hell and potentially pretty flawed but i'm dead tired and i don't care enough right now to rework anything. Lemme know if you have any corrections or backup points to make or anything ig)