Yes, that is a distinct possibility if Neelix is a massive loser with no self esteem.
In retrospect it even makes sense.
I'd even say that they broke up right after Warlord before the next episode started, when Kes confirmed that the Warlord was telling the truth because she was too much of a coward to break it off herself and in a way she's glad that she was possessed because now she is truly free from a depressing burden that captured her every moment which she had no idea how to politely escape from.
But since we didn't see that happen, it might not have happened.
Between Darkling and Warlord their relationship is Schroedingers Cat.
It was in an indeterminate quantum state.
Did we see Sisko and Cassiday get back together? He was drunk on Visions from that orb shadow and acting crazy, So that once all that whacky shit quietened they still had to have a real conversation about whether he was going to share his bed with a terrorist convict?
What about when that Paugh Wraith who took over kieko? "she" wanted to sleep with Miles for a laugh, does that mean that on the inside underneath the possession that Kieko was gagging for a bit too? I doubt they did even after she forced him to share a bed, but if they had, and Yoshi had been conceived then rather than much earlier, you could have argued that kid would grow up to be the emissary of the Paugh Wraiths.