The email exchanges show the FBI was aware - before it secured the now-infamous warrant - that there were intelligence community concerns about the reliability of the main evidence used to support it: the Christopher Steele dossier.
If the FBI knew of his media contacts and the concerns about the reliability of his dossier before seeking the warrant, it would constitute a serious breach of FISA regulations and the trust that the FISA court places in the FBI.
That's because the FBI has an obligation to certify to the court before it approves FISA warrants that its evidence is verified, and to alert the judges to any flaws in its evidence or information that suggest the target might be innocent.