It may be part of the prosecution's case that they plan to use against Rex H. I can't think of any other reason for them to not reveal the information "for now". Good prosecutors usually keep their evidence and trial strategy under wraps. They don't want to try their case in the news media. That can result in public opinion influencing the jury and usually gives the defense attorneys a good argument for mistrial.
Some additional details/evidence that can be used against Rex H., aside from what we already know, probably won't come out until trial. That said, if they come up with anything really relevant from their search of Rex H's home, they may reveal it.
If prosecution starts discussing details of police corruption during the Gilgo 4 investigation, the defense will absolutely take that and run with it in the news and social media. They'll use it to undermine the prosecution's case, taint the potential jury pool and make the public question the honesty of the current investigation.
I don't want to hear the details. John Ray is leaking stuff that's harmful to Rex H and Burke, but I don't think he'll say anything that will compromise the DA's case. JMO
I'm willing to wait until the trial to get more details on how the original investigation was screwed up. No doubt the defense team will bring it up then.