Then please explain what the goal of discussing getting rid of blight is. It's not going to happen anytime soon, and thusfar ideas have been focused on material that would probably not occur anymore (Read: NPC-led invasions).
A map retexture might not be that hard, and, as originally suggested by the OP, the affected regions, if uncovered, should probably have some modifications. But then that would likely just bring on a slew of new complaints along the lines of "These regions suck" or "Monster spawning in Eno is too high".
But most importantly, why are we talking more about how to dispel the blight when the more fruitful questions might be what the invaders were doing? The blight was not the central aspect of the 4th Inv (at least it doesn't seem like it because it occurred three months after initiation). But where are discussions about that, OOC post-Invasion sharing of information gathered during the Invasion? There was a short-lived thread on the dlist, but that achieved little more than revealing who played the Light and Undead.
And what do I think about this? I think it's because the blight, and the somewhat increased (more tame now) rogue spawns, affect things tangibly in-game. All this story stuff about the invaders doesn't actually change anything in terms of numbers. Maybe the story aspect isn't lost on anyone, but the vast majority appears to be more concerned with things like region stats, expansion, and things related mechanically to the game. There's nothing wrong with that, and it makes sense. But I think we're looking in the wrong direction if that's our main concern. The 4th Inv was supposed to provide us with a neat story to uncover. Of course, we kind of muddled a bunch of it, but that's expected too. Still, I think the main point was the actual plot, not whatever mechanical things occurred afterwards.