I don't think most of them should be on the timeline. Can't really think of a reason other than that they're ''kid'' versions of the movies, which don't add any new information. Same could be said for the comic adaptions (although they do sometimes add a new scene), but those are included in the prelude comics and contain the red MCU stamp.
Others show behind the scenes of the movies, so no in-universe stories.
Here are a few I'd like to point out:
-Avengers: Infinity War The Journals: I bought this one and returned it. I believe it reference the Heroes' Journey story, but it wasn't anything interesting. I don't know if I ever commented on it here, but this one shouldn't really be considered for the timeline.
-Captain Marvel What Makes a Hero: I always see this when I search for new MCU novels, it's very child-oriented I believe, and doesn't contain a story?
-Spider-Man Far From Home: Spider-Man Swings Through Europe!: Same for this one, not sure what the story is though, probably a retelling of FFH.
-Iron Man - Manual: I'd like this on the timeline, it's similar to the Wakanda Files, and I believe it's written somewhere after Iron Man 3. I'll check if you want it on there
@Lebnyx
-Guardians of the Galaxy Vol. 2 The Movie Special (Comic: Guardians of the Galaxy: Dream On #1)
Thor Ragnarok Official Movie Special (Comic: Thor Where walk the Frost Giants #): Haven't heard of these two, anyone know about them?
-Captain Marvel Starforce Mission Log: Anyone have a epub for this one? Want to know if I should put it in my collection and whether it can be added to the timeline.