I dont know the legality of this but perhaps they feel it would look overly political.
The Biden 2020 Presidential Campaign can sue if they had signed a NDA with Fox. Same for the DNC. According to several legal experts an NDA is routine when signing advertising agreements. Fox clearly violated those agreements. Fox was paid by the campaign to run those ads and they agreed to any and terms in that contract. This is corporate espionage and I am sure Fox never thought they would get caught.
...before it aired would hesitate for one second over concerns of looking "overly political".
We Democrats need to stop bringing butter knives to machine gun fights.
Just going to take sometime. But discovery would be great for the public to know how rigged FOX is.