This is a question that extends to a broader set of questions about continuity snapshots.
At various story points, the NPCs comment on the ongoing story in ways that are often interesting lore. For example, Zeno has a few interesting lines about Melfonseana's arc, Fourie and a couple other NPCs mention their place in the new ARKS organisational structure only early in Episode 4 (I know which branch she is in - do you? If you missed it, you can't find out now), and several characters only make temporary appearances on the ship in the first place. I think even Quna can be spoken to once or twice prior to Episode 4.
These are all missable conversations in a game that is already missing item descriptions on Global. Moreover, anyone who ever does more than one story quest at a time will miss some of what they have to say. The ability to go back and find what certain characters said at different times would be quite useful, you know?