This is messed up, though.
Sure, if you choose to go with Iorveth the nonhumans in Flotsam get slaughtered so it makes sense they are gone. However if you choose Roche there is a big feast in the marketplace - and that's it.
Maybe the devs somehow forgot to differentiate these two storylines for these NPCs?
Er....the slaughter occurs BEFORE you make a choice between the two sides. So, nothing you said makes any sense. :p