While it does seem like a bit of retcon, it makes sense that something like that happened. Also, it worked better for Elan's "arc" to not know why Varsuvius was acting weird, or at least, for V's motivation to not be clearly stated, making V less sympathetic at the time. Similar to the party not knowing about the motivator for Haley's greed, etc.
Also, the getting spells back without sleeping thing is something that needed to be explained (and an elf wizard would know that "rule" because he'd still have to rest 4 hours in addition to the trancing anyway)