Mr Justice Sullivan last week quashed a Charity Commission order allowing the London Borough of Haringey and the Palace Charitable Trust to enter into a 125-year lease with the Firoka Group.
The judge blocked the scheme after agreeing that proper consultation on the 130-year old landmark had not taken place because the lease was not disclosed.
He added that it was "nonsense" that interested parties could not see the details because they were confidential, even though the then Home Office junior minister Fiona MacTaggart promised a consultation.
Save Ally Pally campaigner Jacob O'Callaghan, who sought the judicial review, said it is a "joke" to argue that the public has been consulted on the scheme.
A meeting between the trustees and the Charity Commission was due to be held as Planning went to press to discuss the future of the development.
It could see an order drafted to sell the building and the lease made public. Plans include a 150-bedroom hotel, a casino, restaurants and leisure facilities.
Alexandra Palace Charitable Trust chairman of trustees Matt Cooke said: "The situation whereby 40 per cent of the palace is derelict and the council is forced to support it with hundreds of thousands of pounds each year is not sustainable."