The fluff could be ret-conned so they never got eaten...this is Ward after all!
Dont worry, the Necrons show up to give Eldar a hand, heck even some Noise Marines and Daemons of Slaanesh show up as well. But as the great Farseer pierces the heart of the last hivetyrant and says "This world is ours beast!" the tyrant points to the sky and says "No.....this world is theirs.....". The farseer looks up and sees thousands of drop pods descending on Iyanden! One crashes next to her and as she gets ready to fight it opens up and orks come charging out of it screaming WAAAAAAGHH!!! She charges........
*fap**fap**fap**fap**fap**fap**fap**fap**fap**fap* "-AHHHH YEEAAAHHH! IM THE GREATEST FLUFF WRITER OF ALL TIME!!" Screams Matt Ward as he hands the script to the printing company and they start printing the Iyanden supplement.