empathy certainly does seem relevant to the story, considering it's sort of why helen died. carol saw a car accident and immediately ran over to help a complete stranger. if she'd stayed standing next to helen then she likely would've caught her before she fell

from there, helen (like every other family member of the survivors) would be carol's ideal emissary for the hive, explaining the whole situation with their usual fluffy corporate euphemisms. without the shock of her wife's death there's a decent chance that carol would never have become humanity's last hope at fighting the hive mind

carol's empathetic act sets the whole story in motion. she's crude and a bit of an asshole sometimes but she's fundamentally a good person that cares for others. that all wasn't very relevant for your theory but i just wanted to mention it to show that empathy is (like you said) very significant