The movie established the "magic blood" in the first act when it is used to cure a dying child. The Tribble only reiterates that. Chekhov's Gun.It's not that it's technologically unlikely in Trek, it's that it comes out of nowhere. It's a deus ex machina used because they wanted to have the drama of Kirk's death scene and the Wrath of Khan reprisal without having the actual consequences of Kirk's death. It wasn't even hinted at until the tribble popped back to life just before they brought Kirk back.
The novels are the tail, not the dog.And no one's saying the Gorn have to lay eggs, they're just commenting on the fact that some Trek works have said they do and others have said they don't.