I feel like that might be too on the nose honestly. Firstly, why would he be still around now all these years after Karsus' folly? He's currently a level one wizard. If he's been that way since being depowered then he wouldn't have the means to extend his life enough. And even if he did, surely these centuries would have been long enough to figure out how to get rid of the orb already. He was made weaker, but probably not fundamentally dumber. Secondly, I think it would be more interesting to have him just thematically echo Karsus and have learned the wrong lessons from him initially. Thirdly the bio does say he's from Waterdeep but we know how unreliable those are, apparently.
Also I fully believe that this was always his story, but still, having it laid out for certain feels pretty major.
