I’m trying to work this through from the angle of what we learned in SNW S2E3 Tomorrow and Tomorrow and Tomorrow.
Now that it’s reconfirmed that Star Trek doesn’t have an infinitely ever-branching and expanding multiverse (unlike Marvel or DC), we need to consider how a resilient Prime timeline (river of time) would affect how the fractured timeline in this episode healed - and therefore who would remember what.
In the SNW episode, La’an (and presumably Pelia) are exceptions. Others in the 22nd century aren’t aware that key events like the Eugenics War and Khan’s birth have slipped in time.
So, in Voyager, it seems as though anyone in the crew who did not receive the treatment would not have been able to integrate memories from across the fractured timeline and would only have what they knew in the current one.
As for Janeway, it does raise questions about her foreknowledge. It’s also the case that she would know that the major events related to what they experienced was likely, but it could slip by years, and with sufficiently major interventions the timeline might fork. In fact, the future shown in the episode could have represented a fork that would occur if they did not undo the fracturing.
In fact, the future shown in the episode could have represented a fork that would occur if they did not undo the fracturing.
Well, there’s one future time period shown in the episode (which was maybe a tad risky or thoughtless of the writers?) … it’s far in the future where they’re still in the Delta Quad and Icheb and Naomi Wildman are adults and Chakotay and Janeway are long dead. I think the implication is that they’re dead because of the temporal fracturing, but I don’t recall if that’s made clear.
Nonetheless, that this future time period doesn’t occur, given Endgame, implies that you’re correct. Not sure if Endgame being caused by Future Janeway coming back in time means you wouldn’t see its effects when traveling forward in time from a point before Future Janeway’s arrival.
Otherwise, the episode is suggestive, especially given how much of Future Janeway is mirrored in Shattered’s past Janeway, that alterations caused by this episode lead to Future Janeway’s intervention, even as seeds in Janeway’s mind that eventually take root .