You are quite right - if this turns into a problem on 1-2% of the images, that's still too much since moire will invariably always show up on the "money shots". But if the incidence of moire is 0.1% or less, bird photography will be an area where any extra detail really pays off big.
I'm inclined to roll the dice a bit. In examining my bird photos, the really visible feather patterns are confined to a small percentage of images - very close or macro. Those are rare enough that it might be okay.
I'd really like to have more opinions - especially from anyone who has ever seen moire in feathers or fur.