Yeah, no retcon is needed for her to be given a happy ending/fixed engine optiin, not sure where this is coming from. Its been suggested before here but as a suggestion it could be as easy as having two extra dialogue options. With the gondians and dammon with enriched. Thats the easiest route*
Also id think everyone would agree that if a way to fix her was a implemented. It would be AFTER the gortash fight. Cause god damn sam did an amazing VA for that scene. Theres really nothing wrong with getting a fix after *experiencing no hope left * scenerio
Prime example in the game. You assume as a player wylls father is dead, gone, cannot be found, doomed to die as you seal his fate. By refusing to renew wylls contact. Everyones sad. Shocked and dispair sets in. Then by sheer player enginuity (by design by the devs) You can STILL find wylls father and save him defying mizora