Board Thread:Questions and Answers/@comment-5105419-20131130142942/@comment-1173941-20131130143750

They were never mentioned again after Kirito's battle with them, so who knows.

I will say that anything we say would be complete speculation, but I would assume they were just completely discarded, after ALO's "Grand Quest" was removed, and everyone was given Unlimited Flight.

But it's not entirely impossible that they'd use them for some other quest, or something of the sort.