I think they will slowly reveal more and more about their culture and objective.... Cause if they tell it all at once, no suspense
But then we're expected to believe Ericka is this great FBI agent. What FBI agent wouldn't quiz Ryan about his people and why they're here? That would be the first thing any law enforcement person would do. Why try to kidnap a V in the last episode to get answers? They have Ryan right there! Can't he give answers?
If they actually showed a tiny clip of maybe the end of a converation between Ericka and Ryan where she indicates he has told them about the V culture and why he thinks they are on Earth, I can live with waiting for the show to reveal itself. However, it doesn't even seem like Ericka has had such a conversation with Ryan and that makes it hard to buy into the fact she's some super agent.