Well, if Hope has a medical crisis, maybe Aiden was brought back to ensure her husband is available to make decisions when she has this crisis. If he makes a decision that saves her life, she could possibly lose what little of the Salem brain she has and give him just one more chance. Or maybe her medical crisis (or injury in the explosion) causes amnesia and she has lost her short term memory (only remembers being in love with Aiden) and is too fragile to be told the truth. With these writers, Aiden may authorize an amputation or something and we can see the limb grow back a la Philip Kiriakis.