Originally Posted by
Vaedan
She could sense the difference either in Light essence of the M'uru's core or arcane energies of harvested Nether... or both.
Either way, I think it is enough evidence to assume that modern Sunwell is different to the original one, which was made purely out of Well of Eternity. We also looted vial with waters of Well from Kael after his first defeat in Tempest Keep, so I believe none of this water used to restore Sunwell - he no longer had it.
Sure, new blood elf customizations like golden eyes and dark skin might not be direct result of new Sunwell, but seeing new NPCs using these customizations, it pretty much make these character features canon for the race.