Did I tell you about how Seska was retroactively introduced into continuity?
Berman got their season one scripts back from their writers at basically the same time but when they received State of Flux, it was like the best ever... They like marvelled!
"Wow! Gosh, isn't a pity that we didn't tell anyone else to write about Seska before now? there's like 8 episodes before State of Flux she could be skeeving around making trouble but... hey? why don't we just write her in? I mean we are in charge. We can do anything we damn well want!"
Just think about this.
If Voyagers producers were willing to mutilate several locked "original" scripts, to make later episodes make more sense once, then they could in theory do it again.
They could have tucked Lindsay Ballard into 10 episodes before Ashes to Ashes (maybe Fairhaven?) or put Jetal in 5 or 10 episodes before Latent Image (in Once Upon a time... Fuck, are we positive that Ensign Jetal wasn't just another rewrite on his program because the Doctor couldn't handle Sam Wildman dying?)?
But they didn't.
Voyager had almost no foreshadowing (Before and After) and even when they did they cocked it up (Jenny, you're fired. Pack your bags and bugger off.) even though Foreshadowing is piss easy when you're writing 8 to ten scripts at the same time before the actors even get back from break.
Here's why... A multi-episode contract costs more per episode to retain an actor, and it probably fracks with their per episode budget too if they don't get creative.