For NJ, the Fortress looses its old ability. There is no precedent for cards losing Identifiers, but the way I imagined it is that if a card looses a "holds" identifier, the cards it was holding go back to their default locations. One of the side-benefits I envisioned was being able to get back all your cards from Storehouse at once at the cost of losing further use of it and not being able to negate your opponents' Fortresses.