People drifting apart and relationships changing due to altered feelings/circumstances/etc. isn't a poly thing. It's universal. Even committed relationships/marriages end. This is why all of Halsin's talk about hearts being free sounds a bit strange to me - none of my characters are casting permanent compulsions on their romance partners. Maybe the relationships will end someday. Maybe not. That's life.

I don't at all expect them to make Halsin not poly, but I'd at least like an option to go off together with him when the game is over, like we get with all the other love interests. Sure, some conversation about what happens if/when he finds someone else would be nice - do we just not talk about it? does our relationship turn into "just friends" for awhile? - but that's not as necessary, I can headcanon all that myself. (And if you assume that my headcanon would involve him just happening to never fall for someone else again - you would be correct. hahaha)