I mean, like... does any of it matter? The personal stories of the Mitakihara group are the focus regardless, and nothing has changed, regardless.
The cosmological make-up of the setting is interesting but not really relevant until Sabrina meets a god or starts traversing alternate realities.
I mean, our latest talk with Oriko pretty heavily implies that Feathers will exist in all timelines Homura visits from here on. Feathers wouldn't be as much of a problem for Homura as a "new threat" if she Homura could just loop forwards and avoid her.
(Also on the multiverse note, it's worth noting that, while we've never asked Homura about a video diary, Sayakaquest's mechanics still show up in multiple places.)
I don't think it's a thing that would happen. Not because your reasoning is incorrect, but because the premise is faulty.
Her Wish depends on whether she wants to protect Madoka, not whether she's able, deserving, or actually does need to protect her from a real threat.
Long story short, there is that Wraith Arc manga, and Homura still retains her timestop powers throughout it, despite:
1) Actual doubts Madoka exists and is not a fruit of her imagination created by her memory magic in her desperate need to have any friend at all, even if imaginary one
2) Her using the time travel function being dangerous to Madokami, because weird space shenanigans and something something UKG inside the shield
3) Madokami becoming an honest to Urobuchi Law of the universe and thus not really needing any protection Homura is able to provide
In other words, Homura's previous Wish is seemingly obsolete, dangerous and maybe not even real at all, but Homura still retains her powers anyway, because she still wants to meet Madoka again and she still wants to protect her.
The problem with this analogy is that this is not a problem of situation. Oriko doesn't reject her wish she she's captured, she rejects it when she her methods and way of living.
In contrast, Homura during Rebellion and Wraith Arc, was still in her "Fine, I'll do it myself" mode. The plans she makes and actions she takes are those of someone who trusts only herself and relies on no one else. Same as during the loops. Her doubts of Madoka's existence during Wraith arc are because she literally rewrites her mind. And not only has she not rejected or questioned that philosophy in Rebellion, the events there are arguably caused by backsliding
to that mindset.
Here in PMAS, on the other hand, we're spinning doubts in her head as to whether she's even
adequate to protect Madoka.
This ties into timeline worries. For myself, when I see her worries, it's less that this one great timeline will fail... and more that she's been put at a loss by being shown up by us doing what she cannot. That our success makes her think that she's not capable to the task and never was. To the point where we have to continually reassure her of the opposite.
That's why she might reject her wish and why stuff like this:
Also we're trying to make Homura internalize that this is the last timeline, and making her set up contingencies for our failure will not do that. If we can't have unflappable faith that the loop ends here, Homura won't.
Quite frankly, alarms me.
"Internalizing that this is the last timeline" doesn't strike me as something that will be a source of strength for Homura. Quite the opposite. Because internalizing that doesn't mean just mean she believes it will succeed, it means that there's
nothing she can do better than us.
It's imposing our own fears upon her: That if we fail, the quest ends and nothing beyond that can change.
From someone who likes to vote and plan from the mindset of Sabrina being an actual person I'm pretty sure that, in character, that translates to: "If Sabrina dies, nothing I have done matters."
That's not healthy for Sabrina, and it's
certainly not healthy for Homura. Because it means the worst case in my eyes isn't that we simply fail.
It's that Homura decides that failure means we're inadequate... and so is she.
Homura's
strength isn't certain victory: It's her ability to put her failures behind her and move forwards anyways. What she needs isn't the idea that this one attempt will succeed, what she
needs to feel is that she does not need to do this alone, and that she is
not alone.
"This is the last timeline, the one attempt that matters" as a concept? Is at war with everything she's made her strength: It opposes the idea that she can get up and try again, and does not necessarily solve her issues with relying on other people.
Accepting that failure is a possibility is not weakness or cowardice.
It's just one more thing to plan for.
