There's the possibility all of those were simply added for flavour, and it's more akin to seeing Velah plotting the events of Vault of Night out in the House P bar, rather than an actual quest mechanic. So players may be overthinking things.
We also must remind ourselves that this isn't the actual end of the story. And that some of those elements may be brought up again in a future adventure pack, much like how new NPCs were added around Stormreach as new content was about to be launched that related to them. With future actual Wizards content relating to Vecna, some stuff may not be allowed to SSG to deploy right now until it is released first.
So in either event, players may be jumping the gun a bit on that front, even though things in game would allude to it.
J1NG