Annorax was altering the timeline continuously for 200 years from his perspective.
(His weapon was targeting the same year for two centuries, because he was anchored to 2374 for 20 decades, with perhaps a little drift to explain why the badly written story seemed linear. He had not started to play with time in 2174, or his wife would be dead. Don't be a fucking moron.)
We had little evidence to believe that Before and After had not HAPPENED until the episode before Year of Hell finished, which is an intermediate zone when we don't see where the THOUSANDS of different timelines created by Annorax play out and then become aborted and reset, rejiggered, start fresh and then again aborted, ad infinitum.
200 years of this shit.
We did not experience the first couple centuries of Year of Hell where Before and After had sometimes happened, and other times had not happened, depending on how Annorax molested time at any given moment.
Although...
Captain Chakotay had not encountered the Borg in Before and After, or at least got through the Northwest Passage unmolested without picking up a blonde hitch-hiker, and somehow made up the 10k light years Dark Kes gifted Voyager upon her departure, so that the Year of Hell happened approximately at the same time in both timelines.
This is when you begin to wonder what the Queens time capsule broad cast in First Contact from her interplexing beacon had on the condition and girth of Borg Space, sure Annorax may have destroyed/neutered the Borg quite early in his experiments, and then brought them back considering the events of Scorpion which still had to happen after a fashion since Seven of Nine was part of Voyager's crew, but without the Future Queens help the Borg wouldn't have had the tech to bother 8472, even if there's no 8472 there's no North West passage, but if Ransom found a Wormhole that allowed him to skip Borg Space with complete ignorance maybe Captain Chakotay used the same hole?
Here's the Rub.
In any timeline where Kes warns Janeway about the Krenim, of which there would have been thousands, that creates a situation where Janeway is able to negotiate/outwit/survive/avoid the temporally native Krenim (Who are playthings to Annorax just like Janeway.) , so that she is beneath Annorax's attention and equally completely ignorant of Annorax and so eventually & unavoidably falls prey to a reset by Annorax's weapon.
We saw a tiny, tiny, tiny fraction of the story.
The Janeway entering Krenim Space at the Beginning of Year of Hell, after 200 years of Annorax fiddling with her, is not the Janeway at the end of Year of Hell entering Krenim Space who is a fresh faced virgin. The Janeway at the end of Year of Hell, after the destruction of Annnorax's weapon, may have, and most probably did experience Before and After which is why she didn't fly off her handle when she was asked to go around.