I have so many thoughts post Pluribus finale but my current working theory is the virus is a memory monster. There are no truly "active" hive participants. The "real" Zosia is no more accessible to the hive/virus than Helen is, her body just survived the joining and is therefore something to be put to use. The virus robs the bodies of a given planet of their memories, and being that it's incapable of gaining additional knowledge by other means, it then outsources its "gift" to other planets in the name of its biological imperative, which is survival of the virus and not the host bodies.
Survival is human nature. This virus does not prioritize human survival in any sense. There is no human collective.
"Zosia" had such an odd reaction to Carol's phrasing of the question about Zosia's former partner being "in there with them", beyond simply skirting around Carol's evident possessiveness/guilt. In addition, "Zosia" slipping up in episode 8 by starting with "we", correcting to "she could..." before an eventual "I". *We*/*I* is *Us*, all imply an equal ownership, in a sense, with Zosia being an active participant. "She" is something completely other/separate, it's workshopping the performance of the actress cast in Carol's personal romcom, a collaboration with *Carol*, not the other members of some collective.
When asked about Zosia's favorite food, the hive shares a detailed memory rather than outright stating a preference. To connect, sure, but I think memory is the lens with with they filter all human understanding and therefore it's the crutch they use to relate to Carol. The new experience/information they/it gleans from Carol by simply talking to her is alien to them, and their reliance on Helen's memories/personality grows more transparent and cloying as time goes on.
And, man...Kusimayu's smile, her immediate silence...that's a death mask. They all wear one. Zosia slipped back into hers once she gave Carol the ick (*it* miscalculated).
Anyway, it's 2am and this is less than coherent but...wow, what a season of television.