Posted 24 May 2014 - 01:28 PM
I'm sure you saw the entry about the difference between "play" and "put into play" in the FAQ because your definition for playing cards (from your hand during your turn as active player in Marshalling) is more-or-less that FAQ entry. So it should be clear that bringing a card out if Shadows is a "put into play" effect because it does not match that definition (it doesn't have to be during your turn as active player in Marshalling, it doesn't come from your hand, and you are not paying the full cost as defined in the Shadows rules). So you can bring a location out of Shadows without getting into trouble from Reaver's Song.
All other aspects of the question are in the Shadows rules - although "some assembly is required." The Shadow rules say that cards in Shadows are neither in play nor in your hand. That means that playing a card into Shadows cannot be "playing" a card under the definition you spotted earlier because the card goes from hand to a game area that is not "in play." Further, since you are putting the card into Shadows face down, it has no identity as a location, character, etc. (This is the same reason you can play a copy of a unique card into Shadows that you already have in play or in the dead pile; since the identity of the card is hidden, and the Shadows area is not "in play," no rules for unique cards are broken).
So playing a card into Shadows is not considered "playing a location." Combine that with the earlier explanation that bringing a card out of Shadows is not "playing" a location, either, and you're right: Shadow locations are not affected by the "cannot play" limitation on Reaver's Song.