Destroyed Unit

[Nabterayl]

I've always considered it a disembark move as opposed to a disembark materialization.

I agree that's the reasonable way to play it - indeed, the only reasonable way to play it. However, I think it's plain from the rules that it (and all other disembarkations) really is a disembark materialization. I wouldn't insist on the letter of that particular rule unless I felt my opponent was being unsportsmanlike, but if I felt like being unsportsmanlike in return, I'd certainly insist on the letter of the rule.