Most memorable NPCs outside of main scenario or sidequests?

[Keever]

-snip-

All parts of this story are still visible ingame. You can go back and see the earlier parts, nothing's been removed from the game. I believe some of them are dependent on the ingame time-of-day.

[Atoli]

I've stayed next to those places for several ingame days, I went there at all kinds of daytimes, nothing but the current patch's scenario ever appeared.
So no, I'm pretty sure you can't see everything anymore. Even the link you provided states in which patch which part of the story was visible.