I would recommend duplicating it, removing all the classes, then adding the archetypes. Then put your new snippet in the topic template, removing the old.
So "Classes" gets duplicated to "Archetype"
Remove all entries from Archetype
Add new ones (Street-Sam, Face, Decker, Mage, etc...)
Go to the Templates where the Class Snippet is, and remove it.
Add the Archetype snippet in its place.
This would help keep out the possible issues when the marketplace comes out, or issues that may occur with sharing with your players.
At least, that WAS best practices a few months ago. I started copying all templates, and making new ones when I customize now, including Topics. Just to be safe.
I know I take it overboard, but that's just what I do.
You "in theory" could just delete "Fighter, Rogue, etc..." and put in "Shaman, Face, Technomancer" but You'd have to ask Rob on that.
As for your Organizations:Corporations for secret stuff... I'd actually put the base common knowledge in the overview for each one, and then reveal ONLY that. It won't tip them off as to who's pulling strings if you put in as many as you can (i.e. not just Horizon and Ares, but also K.E., L.S., ViaComSoft, etc...)
You'd actually have enough info that they'd not know where to look.
AND, you can keep adding them in as you get time. This makes them think that you're still putting in entries, throwing them off the scent that 3/5 of the first set were directly involved.
Just a thought.