Potentially it does disqualify it, if any hint of collusion could result in hades Vault in Marcone’s Bank from not backing onto the Vault in Hades Realm then having the same space used for a different purpose would do the same thing, especially if there is another candidate which doesn’t have that dual purpose.
There is also the point that both the Gatekeeper and the Winter Lady used the Never Never route to Demonreach. Neither has any known association with Hades or Tartarus, both have associations with Mab and Arctis Tor. Mab will leak information to find out those she cannot trust and wait for them to prove her right, she did this with Nameless, perhaps she did the same with Maeve and the back door to Demonreach, indeed the attack may have been an attempt to verify the information by Maeves allies as much as release Lea. It was shut to her after this, suggesting Mab’s game.
People might want Demonreach to back onto Tartarus, bur there is no evidence for this, but there is circumstantial evidence for Mab’s Ice Garden, by those who have used the route to get there.