glad you tested it, i didn't want to chance data loss.
i would think that a NAS box would be shoved off in a dark corner somewhere and the user would expect it to be available whenever they wanted data off it. personally, my first thought after power is restored isn't "welp, better go turn on the nas!" it's more like "about time. great, now i've gotta reset the clocks on the stove, microwave, radio, etc."